GLUSboolean init(GLUSvoid)
{
GLUStextfile vertexSource;
GLUStextfile fragmentSource;
GLUStgaimage image;
GLUSshape plane;
glusFileLoadText("shader/texture.vert.glsl", &vertexSource);
glusFileLoadText("shader/grey.frag.glsl", &fragmentSource);
glusProgramBuildFromSource(&g_program, (const GLchar**) &vertexSource.text, 0, 0, 0, (const GLchar**) &fragmentSource.text);
glusFileDestroyText(&vertexSource);
glusFileDestroyText(&fragmentSource);
//
// Retrieve the uniform locations in the program.
g_modelViewProjectionMatrixLocation = glGetUniformLocation(g_program.program, "u_modelViewProjectionMatrix");
g_textureLocation = glGetUniformLocation(g_program.program, "u_texture");
g_vertexLocation = glGetAttribLocation(g_program.program, "a_vertex");
g_texCoordLocation = glGetAttribLocation(g_program.program, "a_texCoord");
//
// Load the image.
glusImageLoadTga("../../media/desert.tga", &image);
// Generate and bind a texture.
glGenTextures(1, &g_texture);
glBindTexture(GL_TEXTURE_2D, g_texture);
// Transfer the image data from the CPU to the GPU.
glTexImage2D(GL_TEXTURE_2D, 0, image.format, image.width, image.height, 0, image.format, GL_UNSIGNED_BYTE, image.data);
// Setting the texture parameters.
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
glBindTexture(GL_TEXTURE_2D, 0);
//
// Use a helper function to create a rectangular plane.
glusShapeCreateRectangularPlanef(&plane, (GLfloat) image.width / 2.0f, (GLfloat) image.height / 2.0f);
// Destroying now the image, as the width and height was used above.
glusImageDestroyTga(&image);
// Store the number indices, as we will render with glDrawElements.
g_numberIndicesPlane = plane.numberIndices;
glGenBuffers(1, &g_verticesVBO);
glBindBuffer(GL_ARRAY_BUFFER, g_verticesVBO);
glBufferData(GL_ARRAY_BUFFER, plane.numberVertices * 4 * sizeof(GLfloat), (GLfloat*) plane.vertices, GL_STATIC_DRAW);
glGenBuffers(1, &g_texCoordsVBO);
glBindBuffer(GL_ARRAY_BUFFER, g_texCoordsVBO);
glBufferData(GL_ARRAY_BUFFER, plane.numberVertices * 2 * sizeof(GLfloat), (GLfloat*) plane.texCoords, GL_STATIC_DRAW);
glBindBuffer(GL_ARRAY_BUFFER, 0);
// Generate a VBO for the indices.
glGenBuffers(1, &g_indicesVBO);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, g_indicesVBO);
glBufferData(GL_ELEMENT_ARRAY_BUFFER, plane.numberIndices * sizeof(GLuint), (GLuint*) plane.indices, GL_STATIC_DRAW);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
// Now we can destroy the shape, as all data is now on the GPU.
glusShapeDestroyf(&plane);
//
glUseProgram(g_program.program);
glGenVertexArrays(1, &g_vao);
glBindVertexArray(g_vao);
glBindBuffer(GL_ARRAY_BUFFER, g_verticesVBO);
glVertexAttribPointer(g_vertexLocation, 4, GL_FLOAT, GL_FALSE, 0, 0);
glEnableVertexAttribArray(g_vertexLocation);
glBindBuffer(GL_ARRAY_BUFFER, g_texCoordsVBO);
glVertexAttribPointer(g_texCoordLocation, 2, GL_FLOAT, GL_FALSE, 0, 0);
glEnableVertexAttribArray(g_texCoordLocation);
// Also bind the indices to the VAO.
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, g_indicesVBO);
//
// Also bind created texture ...
glBindTexture(GL_TEXTURE_2D, g_texture);
// ... and as this is texture number 0, bind the uniform to the program.
glUniform1i(g_textureLocation, 0);
//
glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
return GLUS_TRUE;
}
GLUSboolean init(GLUSvoid)
{
GLUStextfile vertexSource;
GLUStextfile fragmentSource;
GLUStextfile computeSource;
GLUSshape plane;
glusFileLoadText("../Example21/shader/texture.vert.glsl", &vertexSource);
glusFileLoadText("../Example21/shader/texture.frag.glsl", &fragmentSource);
glusProgramBuildFromSource(&g_program, (const GLchar**) &vertexSource.text, 0, 0, 0, (const GLchar**) &fragmentSource.text);
glusFileDestroyText(&vertexSource);
glusFileDestroyText(&fragmentSource);
glusFileLoadText("../Example21/shader/texture.comp.glsl", &computeSource);
glusProgramBuildComputeFromSource(&g_computeProgram, (const GLchar**) &computeSource.text);
glusFileDestroyText(&computeSource);
//
// Retrieve the uniform locations in the program.
g_modelViewProjectionMatrixLocation = glGetUniformLocation(g_program.program, "u_modelViewProjectionMatrix");
g_textureLocation = glGetUniformLocation(g_program.program, "u_texture");
g_vertexLocation = glGetAttribLocation(g_program.program, "a_vertex");
g_texCoordLocation = glGetAttribLocation(g_program.program, "a_texCoord");
g_computeTextureLocation = glGetUniformLocation(g_computeProgram.program, "u_texture");
//
// Generate and bind a texture.
glGenTextures(1, &g_texture);
glBindTexture(GL_TEXTURE_2D, g_texture);
// Create an empty image.
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, g_imageWidth, g_imageHeight, 0, GL_RGBA, GL_UNSIGNED_BYTE, 0);
// Setting the texture parameters.
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
glBindTexture(GL_TEXTURE_2D, 0);
//
// Use a helper function to create a rectangular plane.
glusShapeCreateRectangularPlanef(&plane, (GLfloat) g_imageWidth / 2.0f, (GLfloat) g_imageHeight / 2.0f);
// Store the number indices, as we will render with glDrawElements.
g_numberIndicesPlane = plane.numberIndices;
glGenBuffers(1, &g_verticesVBO);
glBindBuffer(GL_ARRAY_BUFFER, g_verticesVBO);
glBufferData(GL_ARRAY_BUFFER, plane.numberVertices * 4 * sizeof(GLfloat), (GLfloat*) plane.vertices, GL_STATIC_DRAW);
glGenBuffers(1, &g_texCoordsVBO);
glBindBuffer(GL_ARRAY_BUFFER, g_texCoordsVBO);
glBufferData(GL_ARRAY_BUFFER, plane.numberVertices * 2 * sizeof(GLfloat), (GLfloat*) plane.texCoords, GL_STATIC_DRAW);
glBindBuffer(GL_ARRAY_BUFFER, 0);
// Generate a VBO for the indices.
glGenBuffers(1, &g_indicesVBO);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, g_indicesVBO);
glBufferData(GL_ELEMENT_ARRAY_BUFFER, plane.numberIndices * sizeof(GLuint), (GLuint*) plane.indices, GL_STATIC_DRAW);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
// Now we can destroy the shape, as all data is now on the GPU.
glusShapeDestroyf(&plane);
//
glUseProgram(g_program.program);
glGenVertexArrays(1, &g_vao);
glBindVertexArray(g_vao);
glBindBuffer(GL_ARRAY_BUFFER, g_verticesVBO);
glVertexAttribPointer(g_vertexLocation, 4, GL_FLOAT, GL_FALSE, 0, 0);
glEnableVertexAttribArray(g_vertexLocation);
glBindBuffer(GL_ARRAY_BUFFER, g_texCoordsVBO);
glVertexAttribPointer(g_texCoordLocation, 2, GL_FLOAT, GL_FALSE, 0, 0);
glEnableVertexAttribArray(g_texCoordLocation);
// Also bind the indices to the VAO.
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, g_indicesVBO);
//
// Also bind created texture ...
glBindTexture(GL_TEXTURE_2D, g_texture);
// ... and bind this texture as an image, as we will write to it.
glBindImageTexture(0, g_texture, 0, GL_FALSE, 0, GL_WRITE_ONLY, GL_RGBA8);
// ... and as this is texture number 0, bind the uniform to the program.
glUniform1i(g_textureLocation, 0);
//
glUseProgram(g_computeProgram.program);
// Pass texture number 0 to the compute shader as well.
glUniform1i(g_computeTextureLocation, 0);
//
glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
return GLUS_TRUE;
}
