git.sesse.net Git - movit/blob - flat_input.cpp

   1 #include <string.h>
   2 #include <assert.h>
   3 #include <GL/glew.h>
   4
   5 #include "flat_input.h"
   6 #include "util.h"
   7
   8 FlatInput::FlatInput(ImageFormat image_format, MovitPixelFormat pixel_format, GLenum type, unsigned width, unsigned height)
   9         : image_format(image_format),
  10           pixel_format(pixel_format),
  11           type(type),
  12           pbo(0),
  13           texture_num(0),
  14           needs_update(false),
  15           finalized(false),
  16           output_linear_gamma(false),
  17           needs_mipmaps(false),
  18           width(width),
  19           height(height),
  20           pitch(width)
  21 {
  22         assert(type == GL_FLOAT || type == GL_UNSIGNED_BYTE);
  23         register_int("output_linear_gamma", &output_linear_gamma);
  24         register_int("needs_mipmaps", &needs_mipmaps);
  25 }
  26
  27 FlatInput::~FlatInput()
  28 {
  29         if (pbo != 0) {
  30                 glDeleteBuffers(1, &pbo);
  31                 check_error();
  32         }
  33         if (texture_num != 0) {
  34                 glDeleteTextures(1, &texture_num);
  35                 check_error();
  36         }
  37 }
  38
  39 void FlatInput::finalize()
  40 {
  41         // Translate the input format to OpenGL's enums.
  42         GLenum internal_format;
  43         if (type == GL_FLOAT) {
  44                 internal_format = GL_RGBA16F_ARB;
  45         } else if (output_linear_gamma) {
  46                 assert(type == GL_UNSIGNED_BYTE);
  47                 internal_format = GL_SRGB8_ALPHA8;
  48         } else {
  49                 assert(type == GL_UNSIGNED_BYTE);
  50                 internal_format = GL_RGBA8;
  51         }
  52         if (pixel_format == FORMAT_RGB) {
  53                 format = GL_RGB;
  54                 bytes_per_pixel = 3;
  55         } else if (pixel_format == FORMAT_RGBA_PREMULTIPLIED_ALPHA ||
  56                    pixel_format == FORMAT_RGBA_POSTMULTIPLIED_ALPHA) {
  57                 format = GL_RGBA;
  58                 bytes_per_pixel = 4;
  59         } else if (pixel_format == FORMAT_BGR) {
  60                 format = GL_BGR;
  61                 bytes_per_pixel = 3;
  62         } else if (pixel_format == FORMAT_BGRA_PREMULTIPLIED_ALPHA ||
  63                    pixel_format == FORMAT_BGRA_POSTMULTIPLIED_ALPHA) {
  64                 format = GL_BGRA;
  65                 bytes_per_pixel = 4;
  66         } else if (pixel_format == FORMAT_GRAYSCALE) {
  67                 format = GL_LUMINANCE;
  68                 bytes_per_pixel = 1;
  69         } else {
  70                 assert(false);
  71         }
  72         if (type == GL_FLOAT) {
  73                 bytes_per_pixel *= sizeof(float);
  74         }
  75
  76         // Create PBO to hold the texture holding the input image, and then the texture itself.
  77         glGenBuffers(1, &pbo);
  78         check_error();
  79         glBindBuffer(GL_PIXEL_UNPACK_BUFFER_ARB, pbo);
  80         check_error();
  81         glBufferData(GL_PIXEL_UNPACK_BUFFER_ARB, pitch * height * bytes_per_pixel, NULL, GL_STREAM_DRAW);
  82         check_error();
  83         glBindBuffer(GL_PIXEL_UNPACK_BUFFER_ARB, 0);
  84         check_error();
  85
  86         glGenTextures(1, &texture_num);
  87         check_error();
  88         glBindTexture(GL_TEXTURE_2D, texture_num);
  89         check_error();
  90         glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
  91         check_error();
  92         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, needs_mipmaps ? GL_LINEAR_MIPMAP_NEAREST : GL_LINEAR);
  93         check_error();
  94         glPixelStorei(GL_UNPACK_ROW_LENGTH, pitch);
  95         check_error();
  96         // Intel/Mesa seems to have a broken glGenerateMipmap() for non-FBO textures, so do it here
  97         // instead of calling glGenerateMipmap().
  98         glTexParameteri(GL_TEXTURE_2D, GL_GENERATE_MIPMAP, needs_mipmaps ? GL_TRUE : GL_FALSE);
  99         check_error();
 100         glTexImage2D(GL_TEXTURE_2D, 0, internal_format, width, height, 0, format, type, NULL);
 101         check_error();
 102         glPixelStorei(GL_UNPACK_ROW_LENGTH, 0);
 103         check_error();
 104
 105         needs_update = true;
 106         finalized = true;
 107 }
 108
 109 void FlatInput::set_gl_state(GLuint glsl_program_num, const std::string& prefix, unsigned *sampler_num)
 110 {
 111         glActiveTexture(GL_TEXTURE0 + *sampler_num);
 112         check_error();
 113         glBindTexture(GL_TEXTURE_2D, texture_num);
 114         check_error();
 115
 116         if (needs_update) {
 117                 // Copy the pixel data into the PBO.
 118                 glBindBuffer(GL_PIXEL_UNPACK_BUFFER_ARB, pbo);
 119                 check_error();
 120                 void *mapped_pbo = glMapBufferARB(GL_PIXEL_UNPACK_BUFFER_ARB, GL_WRITE_ONLY);
 121                 memcpy(mapped_pbo, pixel_data, pitch * height * bytes_per_pixel);
 122                 glUnmapBufferARB(GL_PIXEL_UNPACK_BUFFER_ARB);
 123                 check_error();
 124
 125                 // Re-upload the texture from the PBO.
 126                 glPixelStorei(GL_UNPACK_ROW_LENGTH, pitch);
 127                 check_error();
 128                 glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, width, height, format, type, BUFFER_OFFSET(0));
 129                 check_error();
 130                 glPixelStorei(GL_UNPACK_ROW_LENGTH, 0);
 131                 check_error();
 132                 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
 133                 check_error();
 134                 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
 135                 check_error();
 136                 glBindBuffer(GL_PIXEL_UNPACK_BUFFER_ARB, 0);
 137                 check_error();
 138
 139                 needs_update = false;
 140         }
 141
 142         // Bind it to a sampler.
 143         set_uniform_int(glsl_program_num, prefix, "tex", *sampler_num);
 144         ++*sampler_num;
 145 }
 146
 147 std::string FlatInput::output_fragment_shader()
 148 {
 149         return read_file("flat_input.frag");
 150 }