1 #define GL_GLEXT_PROTOTYPES 1
8 #include "flat_input.h"
11 FlatInput::FlatInput(ImageFormat image_format, unsigned width, unsigned height)
12 : image_format(image_format),
15 output_linear_gamma(false),
21 register_int("output_linear_gamma", &output_linear_gamma);
22 register_int("needs_mipmaps", &needs_mipmaps);
25 void FlatInput::finalize()
27 // Translate the input format to OpenGL's enums.
28 GLenum internal_format;
29 if (output_linear_gamma) {
30 internal_format = GL_SRGB8;
32 internal_format = GL_RGBA8;
34 if (image_format.pixel_format == FORMAT_RGB) {
37 } else if (image_format.pixel_format == FORMAT_RGBA) {
40 } else if (image_format.pixel_format == FORMAT_BGR) {
43 } else if (image_format.pixel_format == FORMAT_BGRA) {
46 } else if (image_format.pixel_format == FORMAT_GRAYSCALE) {
47 format = GL_LUMINANCE;
53 // Create PBO to hold the texture holding the input image, and then the texture itself.
54 glGenBuffers(1, &pbo);
56 glBindBuffer(GL_PIXEL_UNPACK_BUFFER_ARB, pbo);
58 glBufferData(GL_PIXEL_UNPACK_BUFFER_ARB, pitch * height * bytes_per_pixel, NULL, GL_STREAM_DRAW);
60 glBindBuffer(GL_PIXEL_UNPACK_BUFFER_ARB, 0);
63 glGenTextures(1, &texture_num);
65 glBindTexture(GL_TEXTURE_2D, texture_num);
67 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
69 glPixelStorei(GL_UNPACK_ROW_LENGTH, pitch);
71 // Intel/Mesa seems to have a broken glGenerateMipmap() for non-FBO textures, so do it here
72 // instead of calling glGenerateMipmap().
73 glTexParameteri(GL_TEXTURE_2D, GL_GENERATE_MIPMAP, needs_mipmaps);
75 glTexImage2D(GL_TEXTURE_2D, 0, internal_format, width, height, 0, format, GL_UNSIGNED_BYTE, NULL);
77 glPixelStorei(GL_UNPACK_ROW_LENGTH, 0);
84 void FlatInput::set_gl_state(GLuint glsl_program_num, const std::string& prefix, unsigned *sampler_num)
86 glActiveTexture(GL_TEXTURE0 + *sampler_num);
88 glBindTexture(GL_TEXTURE_2D, texture_num);
92 // Copy the pixel data into the PBO.
93 glBindBuffer(GL_PIXEL_UNPACK_BUFFER_ARB, pbo);
95 void *mapped_pbo = glMapBufferARB(GL_PIXEL_UNPACK_BUFFER_ARB, GL_WRITE_ONLY);
96 memcpy(mapped_pbo, pixel_data, pitch * height * bytes_per_pixel);
97 glUnmapBufferARB(GL_PIXEL_UNPACK_BUFFER_ARB);
100 // Re-upload the texture from the PBO.
101 glPixelStorei(GL_UNPACK_ROW_LENGTH, pitch);
103 glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, width, height, format, GL_UNSIGNED_BYTE, BUFFER_OFFSET(0));
105 glPixelStorei(GL_UNPACK_ROW_LENGTH, 0);
107 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
109 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
111 glBindBuffer(GL_PIXEL_UNPACK_BUFFER_ARB, 0);
114 needs_update = false;
117 // Bind it to a sampler.
118 set_uniform_int(glsl_program_num, prefix, "tex", *sampler_num);
122 std::string FlatInput::output_fragment_shader()
124 return read_file("flat_input.frag");