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

   1 #define GL_GLEXT_PROTOTYPES 1
   2
   3 #include <string.h>
   4 #include <GL/gl.h>
   5 #include <GL/glext.h>
   6 #include <assert.h>
   7
   8 #include "input.h"
   9 #include "util.h"
  10
  11 Input::Input(ImageFormat image_format, unsigned width, unsigned height)
  12         : image_format(image_format),
  13           needs_update(false),
  14           use_srgb_texture_format(false),
  15           needs_mipmaps(false),
  16           width(width),
  17           height(height)
  18 {
  19         register_int("use_srgb_texture_format", &use_srgb_texture_format);
  20         register_int("needs_mipmaps", &needs_mipmaps);
  21 }
  22
  23 void Input::finalize()
  24 {
  25         // Translate the input format to OpenGL's enums.
  26         GLenum internal_format;
  27         if (use_srgb_texture_format) {
  28                 internal_format = GL_SRGB8;
  29         } else {
  30                 internal_format = GL_RGBA8;
  31         }
  32         if (image_format.pixel_format == FORMAT_RGB) {
  33                 format = GL_RGB;
  34                 bytes_per_pixel = 3;
  35         } else if (image_format.pixel_format == FORMAT_RGBA) {
  36                 format = GL_RGBA;
  37                 bytes_per_pixel = 4;
  38         } else if (image_format.pixel_format == FORMAT_BGR) {
  39                 format = GL_BGR;
  40                 bytes_per_pixel = 3;
  41         } else if (image_format.pixel_format == FORMAT_BGRA) {
  42                 format = GL_BGRA;
  43                 bytes_per_pixel = 4;
  44         } else if (image_format.pixel_format == FORMAT_GRAYSCALE) {
  45                 format = GL_LUMINANCE;
  46                 bytes_per_pixel = 1;
  47         } else {
  48                 assert(false);
  49         }
  50
  51         // Create PBO to hold the texture holding the input image, and then the texture itself.
  52         glGenBuffers(1, &pbo);
  53         check_error();
  54         glBindBuffer(GL_PIXEL_UNPACK_BUFFER_ARB, pbo);
  55         check_error();
  56         glBufferData(GL_PIXEL_UNPACK_BUFFER_ARB, width * height * bytes_per_pixel, NULL, GL_STREAM_DRAW);
  57         check_error();
  58         glBindBuffer(GL_PIXEL_UNPACK_BUFFER_ARB, 0);
  59         check_error();
  60
  61         glGenTextures(1, &texture_num);
  62         check_error();
  63         glBindTexture(GL_TEXTURE_2D, texture_num);
  64         check_error();
  65         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
  66         check_error();
  67         // Intel/Mesa seems to have a broken glGenerateMipmap() for non-FBO textures, so do it here
  68         // instead of calling glGenerateMipmap().
  69         glTexParameteri(GL_TEXTURE_2D, GL_GENERATE_MIPMAP, needs_mipmaps);
  70         check_error();
  71         glTexImage2D(GL_TEXTURE_2D, 0, internal_format, width, height, 0, format, GL_UNSIGNED_BYTE, NULL);
  72         check_error();
  73
  74         needs_update = false;
  75 }
  76
  77 void Input::set_gl_state(GLuint glsl_program_num, const std::string& prefix, unsigned *sampler_num)
  78 {
  79         if (needs_update) {
  80                 // Copy the pixel data into the PBO.
  81                 glBindBuffer(GL_PIXEL_UNPACK_BUFFER_ARB, pbo);
  82                 check_error();
  83                 void *mapped_pbo = glMapBufferARB(GL_PIXEL_UNPACK_BUFFER_ARB, GL_WRITE_ONLY);
  84                 memcpy(mapped_pbo, pixel_data, width * height * bytes_per_pixel);
  85                 glUnmapBufferARB(GL_PIXEL_UNPACK_BUFFER_ARB);
  86                 check_error();
  87
  88                 // Re-upload the texture from the PBO.
  89                 glActiveTexture(GL_TEXTURE0);
  90                 check_error();
  91                 glBindTexture(GL_TEXTURE_2D, texture_num);
  92                 check_error();
  93                 glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, width, height, format, GL_UNSIGNED_BYTE, BUFFER_OFFSET(0));
  94                 check_error();
  95                 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
  96                 check_error();
  97                 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
  98                 check_error();
  99                 glBindBuffer(GL_PIXEL_UNPACK_BUFFER_ARB, 0);
 100                 check_error();
 101
 102                 needs_update = false;
 103         }
 104
 105         // Bind it to a sampler.
 106         set_uniform_int(glsl_program_num, prefix, "tex", *sampler_num);
 107         ++*sampler_num;
 108 }
 109
 110 std::string Input::output_fragment_shader()
 111 {
 112         return read_file("input.frag");
 113 }