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  • Very basic OpenGL ES 2 error

    - by user16547
    This is an incredibly simple shader, yet I'm having a lot of trouble understanding what's wrong with it. I'm trying to send a float to my fragment shader. Its purpose is to adjust the alpha of the fragment colour. Here is my fragment shader: precision mediump float; uniform sampler2D u_Texture; uniform float u_Alpha; varying vec2 v_TexCoordinate; void main() { gl_FragColor = texture2D(u_Texture, v_TexCoordinate); gl_FragColor.a *= u_Alpha; } and below is my rendering method. I get a 1282 (invalid operation) on the GLES20.glUniform1f(u_Alpha, alpha); line. alpha is 1 (but I tried other values as well) and transparent is true: public void render() { GLES20.glUseProgram(mProgram); if(transparent) { GLES20.glEnable(GLES20.GL_BLEND); GLES20.glBlendFunc(GLES20.GL_SRC_ALPHA, GLES20.GL_ONE_MINUS_SRC_ALPHA); GLES20.glUniform1f(u_Alpha, alpha); } Matrix.setIdentityM(mModelMatrix, 0); Matrix.rotateM(mModelMatrix, 0, angle, 0, 0, 1); Matrix.translateM(mModelMatrix, 0, x, y, z); Matrix.multiplyMM(mMVPMatrix, 0, mViewMatrix, 0, mModelMatrix, 0); Matrix.multiplyMM(mMVPMatrix, 0, mProjectionMatrix, 0, mMVPMatrix, 0); GLES20.glUniformMatrix4fv(u_MVPMatrix, 1, false, mMVPMatrix, 0); GLES20.glBindBuffer(GLES20.GL_ARRAY_BUFFER, vbo[0]); GLES20.glVertexAttribPointer(a_Position, 3, GLES20.GL_FLOAT, false, 12, 0); GLES20.glBindBuffer(GLES20.GL_ARRAY_BUFFER, vbo[1]); GLES20.glVertexAttribPointer(a_TexCoordinate, 2, GLES20.GL_FLOAT, false, 8, 0); //snowTexture start GLES20.glActiveTexture(GLES20.GL_TEXTURE0); GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, textureHandle[0]); GLES20.glUniform1i(u_Texture, 0); GLES20.glBindBuffer(GLES20.GL_ELEMENT_ARRAY_BUFFER, ibo[0]); GLES20.glDrawElements(GLES20.GL_TRIANGLE_STRIP, indices.capacity(), GLES20.GL_UNSIGNED_BYTE, 0); GLES20.glBindBuffer(GLES20.GL_ARRAY_BUFFER, 0); GLES20.glBindBuffer(GLES20.GL_ELEMENT_ARRAY_BUFFER, 0); if(transparent) { GLES20.glDisable(GLES20.GL_BLEND); } GLES20.glUseProgram(0); }

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  • OpenGL directional light creating black spots

    - by AnonymousDeveloper
    I probably ought to start by saying that I suspect the problem is that one of my vectors is not in the correct "space", but I don't know for sure. I am having a strange problem with a directional light. When I move the camera away from (0.0, 0.0, 0.0) it creates tiny black spots that grow larger as the distance increases. I apologize ahead of time for the length of the code. Vertex shader: #version 410 core in vec3 vf_normal; in vec3 vf_bitangent; in vec3 vf_tangent; in vec2 vf_textureCoordinates; in vec3 vf_vertex; out vec3 tc_normal; out vec3 tc_bitangent; out vec3 tc_tangent; out vec2 tc_textureCoordinates; out vec3 tc_vertex; uniform mat3 vf_m_normal; uniform mat4 vf_m_model; uniform mat4 vf_m_mvp; uniform mat4 vf_m_projection; uniform mat4 vf_m_view; uniform float vf_te_inner; uniform float vf_te_outer; void main() { tc_normal = vf_normal; tc_bitangent = vf_bitangent; tc_tangent = vf_tangent; tc_textureCoordinates = vf_textureCoordinates; tc_vertex = vf_vertex; gl_Position = vf_m_mvp * vec4(vf_vertex, 1.0); } Tessellation Control shader: #version 410 core layout (vertices = 3) out; in vec3 tc_normal[]; in vec3 tc_bitangent[]; in vec3 tc_tangent[]; in vec2 tc_textureCoordinates[]; in vec3 tc_vertex[]; out vec3 te_normal[]; out vec3 te_bitangent[]; out vec3 te_tangent[]; out vec2 te_textureCoordinates[]; out vec3 te_vertex[]; uniform float vf_te_inner; uniform float vf_te_outer; uniform vec4 vf_l_color; uniform vec3 vf_l_position; uniform mat4 vf_m_depthBias; uniform mat4 vf_m_model; uniform mat4 vf_m_mvp; uniform mat4 vf_m_projection; uniform mat4 vf_m_view; uniform sampler2D vf_t_diffuse; uniform sampler2D vf_t_normal; uniform sampler2DShadow vf_t_shadow; uniform sampler2D vf_t_specular; #define ID gl_InvocationID float getTessLevelInner(float distance0, float distance1) { float avgDistance = (distance0 + distance1) / 2.0; return clamp((vf_te_inner - avgDistance), 1.0, vf_te_inner); } float getTessLevelOuter(float distance0, float distance1) { float avgDistance = (distance0 + distance1) / 2.0; return clamp((vf_te_outer - avgDistance), 1.0, vf_te_outer); } void main() { te_normal[gl_InvocationID] = tc_normal[gl_InvocationID]; te_bitangent[gl_InvocationID] = tc_bitangent[gl_InvocationID]; te_tangent[gl_InvocationID] = tc_tangent[gl_InvocationID]; te_textureCoordinates[gl_InvocationID] = tc_textureCoordinates[gl_InvocationID]; te_vertex[gl_InvocationID] = tc_vertex[gl_InvocationID]; float eyeToVertexDistance0 = distance(vec3(0.0), vec4(vf_m_view * vec4(tc_vertex[0], 1.0)).xyz); float eyeToVertexDistance1 = distance(vec3(0.0), vec4(vf_m_view * vec4(tc_vertex[1], 1.0)).xyz); float eyeToVertexDistance2 = distance(vec3(0.0), vec4(vf_m_view * vec4(tc_vertex[2], 1.0)).xyz); gl_TessLevelOuter[0] = getTessLevelOuter(eyeToVertexDistance1, eyeToVertexDistance2); gl_TessLevelOuter[1] = getTessLevelOuter(eyeToVertexDistance2, eyeToVertexDistance0); gl_TessLevelOuter[2] = getTessLevelOuter(eyeToVertexDistance0, eyeToVertexDistance1); gl_TessLevelInner[0] = getTessLevelInner(eyeToVertexDistance2, eyeToVertexDistance0); } Tessellation Evaluation shader: #version 410 core layout (triangles, equal_spacing, cw) in; in vec3 te_normal[]; in vec3 te_bitangent[]; in vec3 te_tangent[]; in vec2 te_textureCoordinates[]; in vec3 te_vertex[]; out vec3 g_normal; out vec3 g_bitangent; out vec4 g_patchDistance; out vec3 g_tangent; out vec2 g_textureCoordinates; out vec3 g_vertex; uniform float vf_te_inner; uniform float vf_te_outer; uniform vec4 vf_l_color; uniform vec3 vf_l_position; uniform mat4 vf_m_depthBias; uniform mat4 vf_m_model; uniform mat4 vf_m_mvp; uniform mat3 vf_m_normal; uniform mat4 vf_m_projection; uniform mat4 vf_m_view; uniform sampler2D vf_t_diffuse; uniform sampler2D vf_t_displace; uniform sampler2D vf_t_normal; uniform sampler2DShadow vf_t_shadow; uniform sampler2D vf_t_specular; vec2 interpolate2D(vec2 v0, vec2 v1, vec2 v2) { return vec2(gl_TessCoord.x) * v0 + vec2(gl_TessCoord.y) * v1 + vec2(gl_TessCoord.z) * v2; } vec3 interpolate3D(vec3 v0, vec3 v1, vec3 v2) { return vec3(gl_TessCoord.x) * v0 + vec3(gl_TessCoord.y) * v1 + vec3(gl_TessCoord.z) * v2; } float amplify(float d, float scale, float offset) { d = scale * d + offset; d = clamp(d, 0, 1); d = 1 - exp2(-2*d*d); return d; } float getDisplacement(vec2 t0, vec2 t1, vec2 t2) { float displacement = 0.0; vec2 textureCoordinates = interpolate2D(t0, t1, t2); vec2 vector = ((t0 + t1 + t2) / 3.0); float sampleDistance = sqrt((vector.x * vector.x) + (vector.y * vector.y)); sampleDistance /= ((vf_te_inner + vf_te_outer) / 2.0); displacement += texture(vf_t_displace, textureCoordinates).x; displacement += texture(vf_t_displace, textureCoordinates + vec2(-sampleDistance, -sampleDistance)).x; displacement += texture(vf_t_displace, textureCoordinates + vec2(-sampleDistance, sampleDistance)).x; displacement += texture(vf_t_displace, textureCoordinates + vec2( sampleDistance, sampleDistance)).x; displacement += texture(vf_t_displace, textureCoordinates + vec2( sampleDistance, -sampleDistance)).x; return (displacement / 5.0); } void main() { g_normal = normalize(interpolate3D(te_normal[0], te_normal[1], te_normal[2])); g_bitangent = normalize(interpolate3D(te_bitangent[0], te_bitangent[1], te_bitangent[2])); g_patchDistance = vec4(gl_TessCoord, (1.0 - gl_TessCoord.y)); g_tangent = normalize(interpolate3D(te_tangent[0], te_tangent[1], te_tangent[2])); g_textureCoordinates = interpolate2D(te_textureCoordinates[0], te_textureCoordinates[1], te_textureCoordinates[2]); g_vertex = interpolate3D(te_vertex[0], te_vertex[1], te_vertex[2]); float displacement = getDisplacement(te_textureCoordinates[0], te_textureCoordinates[1], te_textureCoordinates[2]); float d2 = min(min(min(g_patchDistance.x, g_patchDistance.y), g_patchDistance.z), g_patchDistance.w); d2 = amplify(d2, 50, -0.5); g_vertex += g_normal * displacement * 0.1 * d2; gl_Position = vf_m_mvp * vec4(g_vertex, 1.0); } Geometry shader: #version 410 core layout (triangles) in; layout (triangle_strip, max_vertices = 3) out; in vec3 g_normal[3]; in vec3 g_bitangent[3]; in vec4 g_patchDistance[3]; in vec3 g_tangent[3]; in vec2 g_textureCoordinates[3]; in vec3 g_vertex[3]; out vec3 f_tangent; out vec3 f_bitangent; out vec3 f_eyeDirection; out vec3 f_lightDirection; out vec3 f_normal; out vec4 f_patchDistance; out vec4 f_shadowCoordinates; out vec2 f_textureCoordinates; out vec3 f_vertex; uniform vec4 vf_l_color; uniform vec3 vf_l_position; uniform mat4 vf_m_depthBias; uniform mat4 vf_m_model; uniform mat4 vf_m_mvp; uniform mat3 vf_m_normal; uniform mat4 vf_m_projection; uniform mat4 vf_m_view; uniform sampler2D vf_t_diffuse; uniform sampler2D vf_t_normal; uniform sampler2DShadow vf_t_shadow; uniform sampler2D vf_t_specular; void main() { int index = 0; while (index < 3) { vec3 vertexNormal_cameraspace = vf_m_normal * normalize(g_normal[index]); vec3 vertexTangent_cameraspace = vf_m_normal * normalize(f_tangent); vec3 vertexBitangent_cameraspace = vf_m_normal * normalize(f_bitangent); mat3 TBN = transpose(mat3( vertexTangent_cameraspace, vertexBitangent_cameraspace, vertexNormal_cameraspace )); vec3 eyeDirection = -(vf_m_view * vf_m_model * vec4(g_vertex[index], 1.0)).xyz; vec3 lightDirection = normalize(-(vf_m_view * vec4(vf_l_position, 1.0)).xyz); f_eyeDirection = TBN * eyeDirection; f_lightDirection = TBN * lightDirection; f_normal = normalize(g_normal[index]); f_patchDistance = g_patchDistance[index]; f_shadowCoordinates = vf_m_depthBias * vec4(g_vertex[index], 1.0); f_textureCoordinates = g_textureCoordinates[index]; f_vertex = (vf_m_model * vec4(g_vertex[index], 1.0)).xyz; gl_Position = gl_in[index].gl_Position; EmitVertex(); index ++; } EndPrimitive(); } Fragment shader: #version 410 core in vec3 f_bitangent; in vec3 f_eyeDirection; in vec3 f_lightDirection; in vec3 f_normal; in vec4 f_patchDistance; in vec4 f_shadowCoordinates; in vec3 f_tangent; in vec2 f_textureCoordinates; in vec3 f_vertex; out vec4 fragColor; uniform vec4 vf_l_color; uniform vec3 vf_l_position; uniform mat4 vf_m_depthBias; uniform mat4 vf_m_model; uniform mat4 vf_m_mvp; uniform mat4 vf_m_projection; uniform mat4 vf_m_view; uniform sampler2D vf_t_diffuse; uniform sampler2D vf_t_normal; uniform sampler2DShadow vf_t_shadow; uniform sampler2D vf_t_specular; vec2 poissonDisk[16] = vec2[]( vec2(-0.94201624, -0.39906216), vec2( 0.94558609, -0.76890725), vec2(-0.09418410, -0.92938870), vec2( 0.34495938, 0.29387760), vec2(-0.91588581, 0.45771432), vec2(-0.81544232, -0.87912464), vec2(-0.38277543, 0.27676845), vec2( 0.97484398, 0.75648379), vec2( 0.44323325, -0.97511554), vec2( 0.53742981, -0.47373420), vec2(-0.26496911, -0.41893023), vec2( 0.79197514, 0.19090188), vec2(-0.24188840, 0.99706507), vec2(-0.81409955, 0.91437590), vec2( 0.19984126, 0.78641367), vec2( 0.14383161, -0.14100790) ); float random(vec3 seed, int i) { vec4 seed4 = vec4(seed,i); float dot_product = dot(seed4, vec4(12.9898, 78.233, 45.164, 94.673)); return fract(sin(dot_product) * 43758.5453); } float amplify(float d, float scale, float offset) { d = scale * d + offset; d = clamp(d, 0, 1); d = 1 - exp2(-2.0 * d * d); return d; } void main() { vec3 lightColor = vf_l_color.xyz; float lightPower = vf_l_color.w; vec3 materialDiffuseColor = texture(vf_t_diffuse, f_textureCoordinates).xyz; vec3 materialAmbientColor = vec3(0.1, 0.1, 0.1) * materialDiffuseColor; vec3 materialSpecularColor = texture(vf_t_specular, f_textureCoordinates).xyz; vec3 n = normalize(texture(vf_t_normal, f_textureCoordinates).rgb * 2.0 - 1.0); vec3 l = normalize(f_lightDirection); float cosTheta = clamp(dot(n, l), 0.0, 1.0); vec3 E = normalize(f_eyeDirection); vec3 R = reflect(-l, n); float cosAlpha = clamp(dot(E, R), 0.0, 1.0); float visibility = 1.0; float bias = 0.005 * tan(acos(cosTheta)); bias = clamp(bias, 0.0, 0.01); for (int i = 0; i < 4; i ++) { float shading = (0.5 / 4.0); int index = i; visibility -= shading * (1.0 - texture(vf_t_shadow, vec3(f_shadowCoordinates.xy + poissonDisk[index] / 3000.0, (f_shadowCoordinates.z - bias) / f_shadowCoordinates.w))); }\n" fragColor.xyz = materialAmbientColor + visibility * materialDiffuseColor * lightColor * lightPower * cosTheta + visibility * materialSpecularColor * lightColor * lightPower * pow(cosAlpha, 5); fragColor.w = texture(vf_t_diffuse, f_textureCoordinates).w; } The following images should be enough to give you an idea of the problem. Before moving the camera: Moving the camera just a little. Moving it to the center of the scene.

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  • OpenGL - Rendering from part of an index and vertex array depending on an element count

    - by user1423893
    I'm currently drawing my shapes as lines by using a VAO and then assigning the dynamic vertices and indices each frame. // Bind VAO glBindVertexArray(m_vao); // Update the vertex buffer with the new data (Copy data into the vertex buffer object) glBufferData(GL_ARRAY_BUFFER, numVertices * sizeof(VertexPosition), m_vertices.data(), GL_DYNAMIC_DRAW); // Update the index buffer with the new data (Copy data into the index buffer object) glBufferData(GL_ELEMENT_ARRAY_BUFFER, numIndices * sizeof(unsigned short), indices.data(), GL_DYNAMIC_DRAW); glDrawElements(GL_LINES, numIndices, GL_UNSIGNED_SHORT, BUFFER_OFFSET(0)); // Unbind VAO glBindVertexArray(0); What I would like to do is draw the lines using only part of the data stored in the index and vertex buffer objects. The vertex buffer has its vertices set from an array of defined maximum size: std::array<VertexPosition, maxVertices> m_vertices; The index buffer has its elements set from an array of defined maximum size: std::array<unsigned short, maxIndices> indices = { 0 }; A running total is kept of the number of vertices and indices needed for each draw call numVertices numIndices Can I not specify that the buffer data contain the entire array and only read from part of it when drawing? For example using the vertex buffer object glBufferData(GL_ARRAY_BUFFER, numVertices * sizeof(VertexPosition), m_vertices.data(), GL_DYNAMIC_DRAW); m_vertices.data() = Entire array is stored numVertices * sizeof(VertexPosition) = Amount of data to read from the entire array Is this not the correct way to approach this? I do not wish to use std::vector if possible.

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  • Indexed Drawing in OpenGL not working

    - by user2050846
    I am trying to render 2 types of primitives- - points ( a Point Cloud ) - triangles ( a Mesh ) I am rendering points simply without any index arrays and they are getting rendered fine. To render the meshes I am using indexed drawing with the face list array having the indices of the vertices to be rendered as Triangles. Vertices and their corresponding vertex colors are stored in their corresponding buffers. But the indexed drawing command do not draw anything. The code is as follows- Main Display Function: void display() { simple->enable(); simple->bindUniform("MV",modelview); simple->bindUniform("P", projection); // rendering Point Cloud glBindVertexArray(vao); // Vertex buffer Point Cloud glBindBuffer(GL_ARRAY_BUFFER,vertexbuffer); glEnableVertexAttribArray(0); glVertexAttribPointer(0,3,GL_FLOAT,GL_FALSE,0,0); // Color Buffer point Cloud glBindBuffer(GL_ARRAY_BUFFER,colorbuffer); glEnableVertexAttribArray(1); glVertexAttribPointer(1,3,GL_FLOAT,GL_FALSE,0,0); // Render Colored Point Cloud //glDrawArrays(GL_POINTS,0,model->vertexCount); glDisableVertexAttribArray(0); glDisableVertexAttribArray(1); // ---------------- END---------------------// //// Floor Rendering glBindBuffer(GL_ARRAY_BUFFER,fl); glEnableVertexAttribArray(0); glEnableVertexAttribArray(1); glVertexAttribPointer(0,3,GL_FLOAT,GL_FALSE,0,0); glVertexAttribPointer(1,4,GL_FLOAT,GL_FALSE,0,(void *)48); glDrawArrays(GL_QUADS,0,4); glDisableVertexAttribArray(0); glDisableVertexAttribArray(1); // -----------------END---------------------// //Rendering the Meshes //////////// PART OF CODE THAT IS NOT DRAWING ANYTHING //////////////////// glBindVertexArray(vid); for(int i=0;i<NUM_MESHES;i++) { glBindBuffer(GL_ARRAY_BUFFER,mVertex[i]); glEnableVertexAttribArray(0); glEnableVertexAttribArray(1); glVertexAttribPointer(0,3,GL_FLOAT,GL_FALSE,0,0); glVertexAttribPointer(1,3,GL_FLOAT,GL_FALSE,0,(void *)(meshes[i]->vertexCount*sizeof(glm::vec3))); //glDrawArrays(GL_TRIANGLES,0,meshes[i]->vertexCount); glBindBuffer(GL_ELEMENT_ARRAY_BUFFER,mFace[i]); //cout<<gluErrorString(glGetError()); glDrawElements(GL_TRIANGLES,meshes[i]->faceCount*3,GL_FLOAT,(void *)0); glDisableVertexAttribArray(0); glDisableVertexAttribArray(1); } glUseProgram(0); glutSwapBuffers(); glutPostRedisplay(); } Point Cloud Buffer Allocation Initialization: void initGLPointCloud() { glGenBuffers(1,&vertexbuffer); glGenBuffers(1,&colorbuffer); glGenBuffers(1,&fl); //Populates the position buffer glBindBuffer(GL_ARRAY_BUFFER,vertexbuffer); glBufferData(GL_ARRAY_BUFFER, model->vertexCount * sizeof (glm::vec3), &model->positions[0], GL_STATIC_DRAW); //Populates the color buffer glBindBuffer(GL_ARRAY_BUFFER, colorbuffer); glBufferData(GL_ARRAY_BUFFER, model->vertexCount * sizeof (glm::vec3), &model->colors[0], GL_STATIC_DRAW); model->FreeMemory(); // To free the not needed memory, as the data has been already // copied on graphic card, and wont be used again. glBindBuffer(GL_ARRAY_BUFFER,0); } Meshes Buffer Initialization: void initGLMeshes(int i) { glBindBuffer(GL_ARRAY_BUFFER,mVertex[i]); glBufferData(GL_ARRAY_BUFFER,meshes[i]->vertexCount*sizeof(glm::vec3)*2,NULL,GL_STATIC_DRAW); glBufferSubData(GL_ARRAY_BUFFER,0,meshes[i]->vertexCount*sizeof(glm::vec3),&meshes[i]->positions[0]); glBufferSubData(GL_ARRAY_BUFFER,meshes[i]->vertexCount*sizeof(glm::vec3),meshes[i]->vertexCount*sizeof(glm::vec3),&meshes[i]->colors[0]); glBindBuffer(GL_ELEMENT_ARRAY_BUFFER,mFace[i]); glBufferData(GL_ELEMENT_ARRAY_BUFFER,meshes[i]->faceCount*sizeof(glm::vec3), &meshes[i]->faces[0],GL_STATIC_DRAW); meshes[i]->FreeMemory(); //glBindBuffer(GL_ELEMENT_ARRAY_BUFFER,0); } Initialize the Rendering, load and create shader and calls the mesh and PCD initializers. void initRender() { simple= new GLSLShader("shaders/simple.vert","shaders/simple.frag"); //Point Cloud //Sets up VAO glGenVertexArrays(1, &vao); glBindVertexArray(vao); initGLPointCloud(); //floorData glBindBuffer(GL_ARRAY_BUFFER, fl); glBufferData(GL_ARRAY_BUFFER, sizeof(floorData), &floorData[0], GL_STATIC_DRAW); glBindBuffer(GL_ARRAY_BUFFER,0); glBindVertexArray(0); //Meshes for(int i=0;i<NUM_MESHES;i++) { if(i==0) // SET up the new vertex array state for indexed Drawing { glGenVertexArrays(1, &vid); glBindVertexArray(vid); glGenBuffers(NUM_MESHES,mVertex); glGenBuffers(NUM_MESHES,mColor); glGenBuffers(NUM_MESHES,mFace); } initGLMeshes(i); } glEnable(GL_DEPTH_TEST); } Any help would be much appreciated, I have been breaking my head on this problem since 3 days, and still it is unsolved.

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  • Black or White Border/Shadow around PNGs in SDL/OPENGL

    - by Dylan
    having the same issue as this: Why do my sprites have a dark shadow/line/frame surrounding the texture? however, when I do the fix suggested there (changing GL_SRC_ALPHA to GL_ONE) it just replaces the black border with a white border on the images, and messes with my background color and some polygons I'm drawing (not all of them weirdly) by making them much lighter... any ideas? heres some of my relevant code. init: glMatrixMode(GL_PROJECTION); glLoadIdentity(); glMatrixMode(GL_MODELVIEW); glLoadIdentity(); glEnable(GL_DEPTH_TEST); glEnable(GL_MULTISAMPLE); glEnable(GL_TEXTURE_2D); glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE); glAlphaFunc(GL_GREATER, 0.01); glEnable(GL_ALPHA_TEST); glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA); glEnable(GL_BLEND); when each texture is loaded: glGenTextures(1, &textureID); glBindTexture(GL_TEXTURE_2D, textureID); gluBuild2DMipmaps(GL_TEXTURE_2D, GL_RGBA, surface->w, surface->h, GL_BGRA, GL_UNSIGNED_BYTE, surface->pixels); glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR); glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);

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  • Rendering Texture Quad to Screen or FBO (OpenGL ES)

    - by Usman.3D
    I need to render the texture on the iOS device's screen or a render-to-texture frame buffer object. But it does not show any texture. It's all black. (I am loading texture with image myself for testing purpose) //Load texture data UIImage *image=[UIImage imageNamed:@"textureImage.png"]; GLuint width = FRAME_WIDTH; GLuint height = FRAME_HEIGHT; //Create context void *imageData = malloc(height * width * 4); CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB(); CGContextRef context = CGBitmapContextCreate(imageData, width, height, 8, 4 * width, colorSpace, kCGImageAlphaPremultipliedLast | kCGBitmapByteOrder32Big); CGColorSpaceRelease(colorSpace); //Prepare image CGContextClearRect(context, CGRectMake(0, 0, width, height)); CGContextDrawImage(context, CGRectMake(0, 0, width, height), image.CGImage); glGenTextures(1, &texture); glBindTexture(GL_TEXTURE_2D, texture); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST); glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, imageData); glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE); glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE); Simple Texture Quad drawing code mentioned here //Bind Texture, Bind render-to-texture FBO and then draw the quad const float quadPositions[] = { 1.0, 1.0, 0.0, -1.0, 1.0, 0.0, -1.0, -1.0, 0.0, -1.0, -1.0, 0.0, 1.0, -1.0, 0.0, 1.0, 1.0, 0.0 }; const float quadTexcoords[] = { 1.0, 1.0, 0.0, 1.0, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0, 1.0, 1.0 }; // stop using VBO glBindBuffer(GL_ARRAY_BUFFER, 0); // setup buffer offsets glVertexAttribPointer(ATTRIB_VERTEX, 3, GL_FLOAT, GL_FALSE, 3*sizeof(float), quadPositions); glVertexAttribPointer(ATTRIB_TEXCOORD0, 2, GL_FLOAT, GL_FALSE, 2*sizeof(float), quadTexcoords); // ensure the proper arrays are enabled glEnableVertexAttribArray(ATTRIB_VERTEX); glEnableVertexAttribArray(ATTRIB_TEXCOORD0); //Bind Texture and render-to-texture FBO. glBindTexture(GL_TEXTURE_2D, GLid); //Actually wanted to render it to render-to-texture FBO, but now testing directly on default FBO. //glBindFramebuffer(GL_FRAMEBUFFER, textureFBO[pixelBuffernum]); // draw glDrawArrays(GL_TRIANGLES, 0, 2*3); What am I doing wrong in this code? P.S. I'm not familiar with shaders yet, so it is difficult for me to make use of them right now.

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  • Drawing flaming letters in 3d on OpenGL ES 2.0

    - by Chiquis
    I am a bit confused about how to achieve this. What i want is to "draw with flames". I have achieved this with textures successfully, but now my concern is about doing this with particles to achieve the flaming effect. Am I supposed to have a Path in where i should add many particle emitters along the path that will "be emitting flames"? I understand the concept for 2d, but for 3d are the particles (that are quads) always supposed to be facing the user? Edit: Something else im worried about is the performance hit that will occur by having that many particle emitters, because there can be many letters and drawings at the same time. And each of these elements will have many particle emitters.

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  • Draw contour around object in Opengl

    - by Maciekp
    I need to draw contour around 2d objects in 3d space. I tried drawing lines around object(+points to fill the gap), but due to line width, some part of it(~50%) was covering object. I tried to use stencil buffer, to eliminate this problem, but I got sth like this(contour is green): http://goo.gl/OI5uc (sorry I can't post images, due to my reputation) You can see(where arrow points), that some parts of line are behind object, and some are above. This changes when I move camera, but always there is some part, that is covering it. Here is code, that I use for drawing object: glColorMask(1,1,1,1); std::list<CObjectOnScene*>::iterator objIter=ptr->objects.begin(),objEnd=ptr->objects.end(); int countStencilBit=1; while(objIter!=objEnd) { glColorMask(1,1,1,1); glStencilFunc(GL_ALWAYS,countStencilBit,countStencilBit); glStencilOp(GL_REPLACE,GL_KEEP,GL_REPLACE ); (*objIter)->DrawYourVertices(); glStencilFunc(GL_NOTEQUAL,countStencilBit,countStencilBit); glStencilOp(GL_KEEP,GL_KEEP,GL_REPLACE); (*objIter)->DrawYourBorder(); ++objIter; ++countStencilBit; } I've tried different settings of stencil buffer, but always I was getting sth like that. Here is question: 1.Am I setting stencil buffer wrong? 2. Are there any other simple ways to create contour on such objects? Thanks in advance. EDIT: 1. I don't have normals of objects. 2. Object can be concave. 3. I can't use shaders(see below why).

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  • Square game map rendered as sphere with OpenGL

    - by Roflha
    Okay so I have been trying to find a good way to do this for a while now and so far I have nothing. For a hobby project of mine I have created a finite voxel world (similar to minecraft), but as I said, mine is finite. When you reach the edge of it, you are sent to the other side. That is all working fine along with rendering the far side of the map, but I want to be able to render this grid as a sphere. Looking down from above, the world is a square. I basically want to be able to represent a portion of that square as a sphere, as if you were looking at a planet. Right now I am experimenting with taking a circular section of the map, and rendering that, but it look to flat (no curvature around the edges). My question then, is what would be the best way to add some curvature to the edges of a 2d circle to make it look like a hemisphere. However, I am not overly attached to this implementation so if somebody has some other idea for representing the square as a planet, I am all ears.

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  • OpenGL VBOs are slower then glDrawArrays.

    - by Arelius
    So, this seems odd to me. I upload a large buffer of vertices, then every frame I call glBindbuffer and then the appropriate gl*Pointer functions with offsets into the buffer, then I use glDrawArrays to draw all of my triangles. I'm only drawing about 100K triangles, however I'm getting about 15FPS. This is where it gets weird, if I change it to not call glBindBuffer, then change the gl*Pointer calls to be actual pointers into the array I have in system memory, and then call glDrawArrays the same, my framerate jumps up to about 50FPS. Any idea what I weird thing I could be doing that would cause this? Did I maybe forget to call glEnable(GL_ALLOW_VBOS_TO_RUN_FAST) or something?

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  • OpenGL Fast-Object Instancing Error

    - by HJ Media Studios
    I have some code that loops through a set of objects and renders instances of those objects. The list of objects that needs to be rendered is stored as a std::map, where an object of class MeshResource contains the vertices and indices with the actual data, and an object of classMeshRenderer defines the point in space the mesh is to be rendered at. My rendering code is as follows: glDisable(GL_BLEND); glEnable(GL_CULL_FACE); glDepthMask(GL_TRUE); glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); glEnable(GL_DEPTH_TEST); for (std::map<MeshResource*, std::vector<MeshRenderer*> >::iterator it = renderables.begin(); it != renderables.end(); it++) { it->first->setupBeforeRendering(); cout << "<"; for (unsigned long i =0; i < it->second.size(); i++) { //Pass in an identity matrix to the vertex shader- used here only for debugging purposes; the real code correctly inputs any matrix. uniformizeModelMatrix(Matrix4::IDENTITY); /** * StartHere fix rendering problem. * Ruled out: * Vertex buffers correctly. * Index buffers correctly. * Matrices correct? */ it->first->render(); } it->first->cleanupAfterRendering(); } geometryPassShader->disable(); glDepthMask(GL_FALSE); glDisable(GL_CULL_FACE); glDisable(GL_DEPTH_TEST); The function in MeshResource that handles setting up the uniforms is as follows: void MeshResource::setupBeforeRendering() { glEnableVertexAttribArray(0); glEnableVertexAttribArray(1); glEnableVertexAttribArray(2); glEnableVertexAttribArray(3); glEnableVertexAttribArray(4); glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, iboID); glBindBuffer(GL_ARRAY_BUFFER, vboID); glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, sizeof(Vertex), 0); // Vertex position glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, sizeof(Vertex), (const GLvoid*) 12); // Vertex normal glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, sizeof(Vertex), (const GLvoid*) 24); // UV layer 0 glVertexAttribPointer(3, 3, GL_FLOAT, GL_FALSE, sizeof(Vertex), (const GLvoid*) 32); // Vertex color glVertexAttribPointer(4, 1, GL_UNSIGNED_SHORT, GL_FALSE, sizeof(Vertex), (const GLvoid*) 44); //Material index } The code that renders the object is this: void MeshResource::render() { glDrawElements(GL_TRIANGLES, geometry->numIndices, GL_UNSIGNED_SHORT, 0); } And the code that cleans up is this: void MeshResource::cleanupAfterRendering() { glDisableVertexAttribArray(0); glDisableVertexAttribArray(1); glDisableVertexAttribArray(2); glDisableVertexAttribArray(3); glDisableVertexAttribArray(4); } The end result of this is that I get a black screen, although the end of my rendering pipeline after the rendering code (essentially just drawing axes and lines on the screen) works properly, so I'm fairly sure it's not an issue with the passing of uniforms. If, however, I change the code slightly so that the rendering code calls the setup immediately before rendering, like so: void MeshResource::render() { setupBeforeRendering(); glDrawElements(GL_TRIANGLES, geometry->numIndices, GL_UNSIGNED_SHORT, 0); } The program works as desired. I don't want to have to do this, though, as my aim is to set up vertex, material, etc. data once per object type and then render each instance updating only the transformation information. The uniformizeModelMatrix works as follows: void RenderManager::uniformizeModelMatrix(Matrix4 matrix) { glBindBuffer(GL_UNIFORM_BUFFER, globalMatrixUBOID); glBufferSubData(GL_UNIFORM_BUFFER, 0, sizeof(Matrix4), matrix.ptr()); glBindBuffer(GL_UNIFORM_BUFFER, 0); }

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  • Drawing flaming letters in 3D with OpenGL ES 2.0

    - by Chiquis
    I am a bit confused about how to achieve this. What I want is to "draw with flames". I have achieved this with textures successfully, but now my concern is about doing this with particles to achieve the flaming effect. Am I supposed to create a path along which I should add many particle emitters that will be emitting flame particles? I understand the concept for 2D, but for 3D are the particles always supposed to be facing the user? Something else I'm worried about is the performance hit that will occur by having that many particle emitters, because there can be many letters and drawings at the same time, and each of these elements will have many particle emitters. More detailed explanation: I have a path of points, which is my model. Imagine a dotted letter "S" for example. I want make the "S" be on fire. The "S" is just an example it can be a circle, triangle, a line, pretty much any path described by my set of points. For achieving this fire effect I thought about using particles. So I am using a program called "Particle Designer" to create a fire style particle emitter. This emitter looks perfect on 2D on the iphone screen dimensions. So then I thought that I could probably draw an S or any other figure if i place many particle emitters next to each other following the path described. To move from the 2D version to the 3D version I thought about, scaling the emitter (with a scale matrix multiplication in its model matrix) and then moving it to a point in my 3D world. I did this and it works. So now I have 1 particle emitter in the 3D world. My question is, is this how you would achieve a flaming letter? Is this too inefficient if i expect to have many flaming paths on my world? Am i supposed to rotate the particle's quad so that its always looking at the user? (the last one is because i noticed that if u look at it from the side the particles start to flatten out)

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  • OpenGL depth texture wrong

    - by CoffeeandCode
    I have been writing a game engine for a while now and have decided to reconstruct my positions from depth... but how I read the depth seems to be wrong :/ What is wrong in my rendering? How I init my depth texture in the FBO gl::BindTexture(gl::TEXTURE_2D, this->textures[0]); // Depth gl::TexImage2D( gl::TEXTURE_2D, 0, gl::DEPTH32F_STENCIL8, width, height, 0, gl::DEPTH_STENCIL, gl::FLOAT_32_UNSIGNED_INT_24_8_REV, nullptr ); gl::TexParameterf(gl::TEXTURE_2D, gl::TEXTURE_MAG_FILTER, gl::NEAREST); gl::TexParameterf(gl::TEXTURE_2D, gl::TEXTURE_MIN_FILTER, gl::NEAREST); gl::TexParameterf(gl::TEXTURE_2D, gl::TEXTURE_WRAP_S, gl::CLAMP_TO_EDGE); gl::TexParameterf(gl::TEXTURE_2D, gl::TEXTURE_WRAP_T, gl::CLAMP_TO_EDGE); gl::FramebufferTexture2D( gl::FRAMEBUFFER, gl::DEPTH_STENCIL_ATTACHMENT, gl::TEXTURE_2D, this->textures[0], 0 ); Linear depth readings in my shader Vertex #version 150 layout(location = 0) in vec3 position; layout(location = 1) in vec2 uv; out vec2 uv_f; void main(){ uv_f = uv; gl_Position = vec4(position, 1.0); } Fragment (where the issue probably is) #version 150\n uniform sampler2D depth_texture; in vec2 uv_f; out vec4 Screen; void main(){ float n = 0.00001; float f = 100.0; float z = texture(depth_texture, uv_f).x; float linear_depth = (n * z)/(f - z * (f - n)); Screen = vec4(linear_depth); // It ISN'T because I don't separate alpha } When Rendered so gamedev.stackexchange, what's wrong with my rendering/glsl?

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  • OpenGL ES multiple objects not being rendered

    - by ladiesMan217
    I am doing the following to render multiple balls move around the screen but only 1 ball is seen to appear and function. I don't know why the rest (count-1) balls are not being drawn public void onDrawFrame(GL10 gl) { // TODO Auto-generated method stub gl.glDisable(GL10.GL_DITHER); gl.glClear(GL10.GL_COLOR_BUFFER_BIT | GL10.GL_DEPTH_BUFFER_BIT); gl.glMatrixMode(GL10.GL_MODELVIEW); gl.glClientActiveTexture(DRAWING_CACHE_QUALITY_HIGH); gl.glLoadIdentity(); for(int i=0;i<mParticleSystem.getParticleCount();i++){ gl.glPushMatrix(); gl.glTranslatef(mParticleSystem.getPosX(i), mParticleSystem.getPosY(i), -3.0f); gl.glScalef(0.3f, 0.3f, 0.3f); gl.glColor4f(r.nextFloat(), r.nextFloat(), r.nextFloat(), 1); gl.glEnable(GL10.GL_TEXTURE_2D); mParticleSystem.getBall(i).draw(gl); gl.glPopMatrix(); } } Here is my void draw(GL10 gl) method public void draw(GL10 gl){ gl.glEnable(GL10.GL_CULL_FACE); gl.glEnable(GL10.GL_SMOOTH); gl.glEnable(GL10.GL_DEPTH_TEST); // gl.glTranslatef(0.2f, 0.2f, -3.0f); // gl.glScalef(size, size, 1.0f); gl.glVertexPointer(3, GL10.GL_FLOAT, 0, vertBuff); gl.glEnableClientState(GL10.GL_VERTEX_ARRAY); gl.glDrawArrays(GL10.GL_TRIANGLE_FAN, 0, points/2); gl.glDisableClientState(GL10.GL_VERTEX_ARRAY); }

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  • C# OpenGL problem with animation

    - by user3696303
    there is a program that simulates a small satellite and requires that a rotation animation of the satellite along the three axes. But when you try to write an animation problem during compilation: the program simply closes (shutdown occurs when swapbuffers, mainloop, redisplay), when you write the easiest programs have the same problem arose. Trying to catch exception by try-catch but here is not exception. How to solve this? I suffer with this a few days. Work in c# visual studio 2008 framework namespace WindowsFormsApplication6 { public partial class Form1 : Form { public Form1() { try { InitializeComponent(); AnT1.InitializeContexts(); } catch(Exception) { Glut.glutDisplayFunc(Draw); Glut.glutTimerFunc(50, Timer, 0); Glut.glutMainLoop(); } } void Timer(int Unused) { Glut.glutPostRedisplay(); Glut.glutTimerFunc(50, Timer, 0); } private void AnT1_Load(object sender, EventArgs e) { Glut.glutInit(); Glut.glutInitDisplayMode(Glut.GLUT_RGB | Glut.GLUT_DOUBLE | Glut.GLUT_DEPTH); Gl.glClearColor(255, 255, 255, 1); Gl.glViewport(0, 0, AnT1.Width, AnT1.Height); Gl.glMatrixMode(Gl.GL_PROJECTION); Gl.glLoadIdentity(); Glu.gluPerspective(45, (float)AnT1.Width / (float)AnT1.Height, 0.1, 200); Gl.glMatrixMode(Gl.GL_MODELVIEW); Gl.glLoadIdentity(); Gl.glEnable(Gl.GL_DEPTH_TEST); Gl.glClear(Gl.GL_COLOR_BUFFER_BIT | Gl.GL_DEPTH_BUFFER_BIT); Gl.glPushMatrix(); double xy = 0.2; Gl.glTranslated(xy, 0, 0); xy += 0.2; Draw(); Glut.glutSwapBuffers(); Glut.glutPostRedisplay(); Gl.glPushMatrix(); Draw(); Gl.glPopMatrix(); } void Draw() { Gl.glLoadIdentity(); Gl.glColor3f(0.502f, 0.502f, 0.502f); Gl.glTranslated(-1, 0, -6); Gl.glRotated(95, 1, 0, 0); Glut.glutSolidCylinder(0.7, 2, 60, 60); Gl.glLoadIdentity(); Gl.glColor3f(0, 0, 0); Gl.glTranslated(-1, 0, -6); Gl.glRotated(95, 1, 0, 0); Glut.glutWireCylinder(0.7, 2, 20, 20); } } }

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  • Mouse Speed in GLUT and OpenGL?

    - by CroCo
    I would like to simulate a point that moves in 2D. The input should be the speed of the mouse, so the new position will be computed as following new_position = old_position + delta_time*mouse_velocity As far as I know in GLUT there is no function to acquire the current speed of the mouse between each frame. What I've done so far to compute the delta_time as following void Display() { glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); glColor3f(1.0f, 0.0f, 0.0f); static int delta_t, current_t, previous_t; current_t = glutGet(GLUT_ELAPSED_TIME); delta_t = current_t - previous_t; std::cout << delta_t << std::endl; previous_t = current_t; glutSwapBuffers(); } Where should I start from here? (Note: I have to get the speed of the mouse because I'm modeling a system) Edit: Based on the above code, delta_time fluctuates so much 34 19 2 20 1 20 0 16 1 1 10 21 0 13 1 19 34 0 13 0 6 1 14 Why does this happen?

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  • Tutorial on OpenGL texture formats

    - by Cyan
    Looking at the documentation glGetTexImage(), one can see that there are plenty of available texture formats. GL_TEXTURE_1D, GL_TEXTURE_2D, GL_TEXTURE_3D, GL_TEXTURE_1D_ARRAY, GL_TEXTURE_2D_ARRAY, GL_TEXTURE_RECTANGLE, GL_TEXTURE_CUBE_MAP_POSITIVE_X, GL_TEXTURE_CUBE_MAP_NEGATIVE_X, GL_TEXTURE_CUBE_MAP_POSITIVE_Y, GL_TEXTURE_CUBE_MAP_NEGATIVE_Y, GL_TEXTURE_CUBE_MAP_POSITIVE_Z, and GL_TEXTURE_CUBE_MAP_NEGATIVE_Z I've only used GL_TEXTURE_2D for the time being. Is there any place / documentation where one can learn about these other formats ? PS : and yes, of course, i've googled for it, results are pretty poor

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  • How to only render part of an image in lwjgl/openGL

    - by Ephyxia
    I'm making a mining/building game in java using slick2D and I want to make it so you can only see a few blocks in any direction while you are underground. The best example I could find of what I want to do is the game miner dig deep. One way I thought of doing it would be to have a large image and just draw transparent areas on it where you need to be able too see but even if that would be an efficient method I wouldn't be sure how to do that.

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  • How to configure background image to be at the bottom OpenGL Android

    - by Maxim Shoustin
    I have class that draws white line: public class Line { //private FloatBuffer vertexBuffer; private FloatBuffer frameVertices; ByteBuffer diagIndices; float[] vertices = { -0.5f, -0.5f, 0.0f, -0.5f, 0.5f, 0.0f }; public Line(GL10 gl) { // a float has 4 bytes so we allocate for each coordinate 4 bytes ByteBuffer vertexByteBuffer = ByteBuffer.allocateDirect(vertices.length * 4); vertexByteBuffer.order(ByteOrder.nativeOrder()); // allocates the memory from the byte buffer frameVertices = vertexByteBuffer.asFloatBuffer(); // fill the vertexBuffer with the vertices frameVertices.put(vertices); // set the cursor position to the beginning of the buffer frameVertices.position(0); } /** The draw method for the triangle with the GL context */ public void draw(GL10 gl) { gl.glEnableClientState(GL10.GL_VERTEX_ARRAY); gl.glVertexPointer(2, GL10.GL_FLOAT, 0, frameVertices); gl.glColor4f(1.0f, 1.0f, 1.0f, 1f); gl.glDrawArrays(GL10.GL_LINE_LOOP , 0, vertices.length / 3); gl.glLineWidth(5.0f); gl.glDisableClientState(GL10.GL_VERTEX_ARRAY); } } It works fine. The problem is: When I add BG image, I don't see the line glView = new GLSurfaceView(this); // Allocate a GLSurfaceView glView.setEGLConfigChooser(8, 8, 8, 8, 16, 0); glView.setRenderer(new mainRenderer(this)); // Use a custom renderer glView.setBackgroundResource(R.drawable.bg_day); // <- BG glView.setRenderMode(GLSurfaceView.RENDERMODE_WHEN_DIRTY); glView.getHolder().setFormat(PixelFormat.TRANSLUCENT); How to get rid of that?

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  • Problem with scrolling background in one OpenGL loop

    - by GvS
    I have 960x3000 map image in png and I'm scrolling it in a loop like this (it's called in 60 FPS loop): glPushMatrix(); glBindTexture( GL_TEXTURE_2D, mapTex[iBgImg]); glBegin(GL_QUADS); double mtstart = 0.0f - fBgVPos/(double)BgSize; double mtend = mtstart + mtsize; glTexCoord2d(0.0, mtstart); glVertex2f(fBgX, TOP_MARGIN); glTexCoord2d(1.0, mtstart); glVertex2f(fBgX + MAP_WIDTH, TOP_MARGIN); glTexCoord2d(1.0, mtend); glVertex2f(fBgX + MAP_WIDTH, BOTTOM_MARGIN); glTexCoord2d(0.0, mtend); glVertex2f(fBgX, BOTTOM_MARGIN); glEnd(); glPopMatrix(); unfortunately it isn't smooth when the game is in windowed mode. However, it is smooth in full screen mode. I'm using GLFW for windows. Maybe there is something wrong with my method? Is there anything better? Or could this be hardware problem? Edit: Window is created using glfwOpenWindowHint(GLFW_WINDOW_NO_RESIZE, GL_TRUE); glfwOpenWindowHint(GLFW_REFRESH_RATE, 60); and main loop is using glfwSwapInterval(1) to ensure 60 FPS;

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  • OpenGL : sluggish performance in extracting texture from GPU

    - by Cyan
    I'm currently working on an algorithm which creates a texture within a render buffer. The operations are pretty complex, but for the GPU this is a simple task, done very quickly. The problem is that, after creating the texture, i would like to save it. This requires to extract it from GPU memory. For this operation, i'm using glGetTexImage(). It works, but the performance is sluggish. No, i mean even slower than that. For example, an 8MB texture (uncompressed) requires 3 seconds (yes, seconds) to be extracted. That's mind puzzling. I'm almost wondering if my graphic card is connected by a serial link... Well, anyway, i've looked around, and found some people complaining about the same, but no working solution so far. The most promising advise was to "extract data in the native format of the GPU". Which i've tried and tried, but failed so far. Edit : by moving the call to glGetTexImage() in a different place, the speed has been a bit improved for the most dramatic samples : looking again at the 8MB texture, it knows requires 500ms, instead of 3sec. It's better, but still much too slow. Smaller texture sizes were not affected by the change (typical timing remained into the 60-80ms range). Using glFinish() didn't help either. Note that, if i call glFinish() (without glGetTexImage), i'm getting a fixed 16ms result, whatever the texture size or complexity. It really looks like the timing for a frame at 60fps. The timing is measured for the full rendering + saving sequence. The call to glGetTexImage() alone does not really matter. That being said, it is this call which changes the performance. And yes, of course, as stated at the beginning, the texture is "created into the GPU", hence the need to save it.

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  • Rendering only a part of text FTGL, OpenGL

    - by Mosquito
    I'm using FTGL library to render text in my C++ project. I can easily render text by using: CFontManager::Instance().renderWrappedText(font, lineLength, position, text); Unfortunately there is a situation in which this Button which displays text, is partly hidden because of resizing container in which it is situated. I'm able without any problem to draw Button's background to fit the container, but I've got a problem with doing the same with a text. Is it possible to somehow draw only text for given width and the rest just ignore? This is a screen which presents my problem: As you can see, the Button "Click here" is being drawn properly, but I can't do the same with "Click here" text.

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  • opengl memory issue - quite strange.

    - by user4707
    Hello, I have heard that textures consumes lot of memory but I am surprised how much.... I have 7 textures 1024 16 bit each. And while I will run my app it consumes 57MB of memory. I think that this is "a bit" too much. I am writing 2D application (no cocos or other framework) Strange is that while I will compile my app with disabled rendering methods: glDrawArrays than It uses only 27MB.... which is about 30MB less... Do you have any Idea why? I am creating textures before rendering of course: rendering looks like this: [EAGLContext setCurrentContext:context]; glBindFramebufferOES(GL_FRAMEBUFFER_OES, defaultFramebuffer); glClearColor(0.0f, 0.0f, 0.0f, 1.0f); glClear(GL_COLOR_BUFFER_BIT); glPushMatrix(); glEnableClientState(GL_VERTEX_ARRAY); glEnableClientState(GL_TEXTURE_COORD_ARRAY); glEnable(GL_TEXTURE_2D); glEnable(GL_BLEND); glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA); TeksturaObrazek *obrazek_klaw =[[AppDirector sharedAppDirector] obrazek_klaw]; glBindTexture(GL_TEXTURE_2D, [[obrazek_klaw image_texture] name] ); glVertexPointer(2, GL_FLOAT, 0,vertex1); glTexCoordPointer(2, GL_FLOAT, 0, vertex2); glColor4f(1,1,1,alpha); glDrawArrays(GL_TRIANGLE_STRIP, 0, 4); glDisable(GL_BLEND); glDisable(GL_TEXTURE_2D); glDisableClientState(GL_TEXTURE_COORD_ARRAY); glPopMatrix(); [context presentRenderbuffer:GL_RENDERBUFFER_OES]; It looks like standard routine... I have spent about 2 days looking for for answer and I still have no clue.

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  • Problem texturing with opengl

    - by Killrazor
    Hello! I'm having problems making a simple sprite rendering. I load 2 different textures. Then, I bind these textures and draw 2 squares, one with each texture. But only the texture of the first rendered object is drawn in both squares. Its like if I'd only use a texture or as if glBindTexture don't work properly. I know that GL is a state machine, but I think that you only need to change active texture with glBindTexture. I load texture with this method: bool CTexture::generate( utils::CImageBuff* img ) { assert(img); m_image = img; CHECKGL(glGenTextures(1,&m_textureID)); CHECKGL(glBindTexture(GL_TEXTURE_2D,m_textureID)); CHECKGL(glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_LINEAR)); CHECKGL(glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_LINEAR)); //CHECKGL(glTexImage2D(GL_TEXTURE_2D,0,img->getBpp(),img->getWitdh(),img->getHeight(),0,img->getFormat(),GL_UNSIGNED_BYTE,img->getImgData())); CHECKGL(glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, img->getWitdh(), img->getHeight(), 0, GL_RGBA, GL_UNSIGNED_BYTE, img->getImgData())); return true; } And I bind textures with this function: void CTexture::bind() { CHECKGL(glBindTexture(GL_TEXTURE_2D,m_textureID)); } Also, I draw sprites with this method void CSprite2D::render() { CHECKGL(glLoadIdentity()); CHECKGL(glEnable(GL_TEXTURE_2D)); CHECKGL(glEnable(GL_BLEND)); CHECKGL(glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA)); m_texture->bind(); CHECKGL(glPushMatrix()); CHECKGL(glBegin(GL_QUADS)); CHECKGL(glTexCoord2f(m_textureAreaStart.s,m_textureAreaStart.t)); // 0,0 by default CHECKGL(glVertex3i(m_position.x,m_position.y,0)); CHECKGL(glTexCoord2f(m_textureAreaEnd.s,m_textureAreaStart.t)); // 1,0 by default CHECKGL(glVertex3i( m_position.x + m_dimensions.x, m_position.y, 0)); CHECKGL(glTexCoord2f(m_textureAreaEnd.s, m_textureAreaEnd.t)); // 1,1 by default CHECKGL(glVertex3i( m_position.x + m_dimensions.x, m_position.y + m_dimensions.y, 0)); CHECKGL(glTexCoord2f(m_textureAreaStart.s, m_textureAreaEnd.t)); // 0,1 by default CHECKGL(glVertex3i( m_position.x, m_position.y + m_dimensions.y,0)); CHECKGL(glPopMatrix()); CHECKGL(glDisable(GL_BLEND)); } Could you help me? All help is welcome. Thanks!!

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  • Particle system lifetimes in OpenGL ES 2

    - by user16547
    I don't know how to work with my particle's lifetimes. My design is simple: each particle has a position, a speed and a lifetime. At each frame, each particle should update its position like this: position.y = position.y + INCREMENT * speed.y However, I'm having difficulties in choosing my INCREMENT. If I set it to some sort of FRAME_COUNT, it looks fine until FRAME_COUNT has to be set back to 0. The effect will be that all particles start over at the same time, which I don't want to happen. I want my particles sort of live "independent" of each other. That's the reason I need a lifetime, but I don't know how to make use of it. I added a lifetime for each particle in the particle buffer, but I also need an individual increment that's updated on each frame, so that when PARTICLE_INCREMENT = PARTICLE_LIFETIME, each increment goes back to 0. How can I achieve something like that?

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