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

   1 #include <string.h>
   2 #include <assert.h>
   3
   4 #include "flat_input.h"
   5 #include "util.h"
   6 #include "opengl.h"
   7
   8 FlatInput::FlatInput(ImageFormat image_format, MovitPixelFormat pixel_format, unsigned width, unsigned height)
   9         : image_format(image_format),
  10           pixel_format(pixel_format),
  11           needs_update(false),
  12           finalized(false),
  13           output_linear_gamma(false),
  14           needs_mipmaps(false),
  15           width(width),
  16           height(height),
  17           pitch(width)
  18 {
  19         register_int("output_linear_gamma", &output_linear_gamma);
  20         register_int("needs_mipmaps", &needs_mipmaps);
  21 }
  22
  23 void FlatInput::finalize()
  24 {
  25         // Translate the input format to OpenGL's enums.
  26         GLenum internal_format;
  27         if (output_linear_gamma) {
  28                 internal_format = GL_SRGB8;
  29         } else {
  30                 internal_format = GL_RGBA8;
  31         }
  32         if (pixel_format == FORMAT_RGB) {
  33                 format = GL_RGB;
  34                 bytes_per_pixel = 3;
  35         } else if (pixel_format == FORMAT_RGBA) {
  36                 format = GL_RGBA;
  37                 bytes_per_pixel = 4;
  38         } else if (pixel_format == FORMAT_BGR) {
  39                 format = GL_BGR;
  40                 bytes_per_pixel = 3;
  41         } else if (pixel_format == FORMAT_BGRA) {
  42                 format = GL_BGRA;
  43                 bytes_per_pixel = 4;
  44         } else if (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, pitch * 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         glPixelStorei(GL_UNPACK_ROW_LENGTH, pitch);
  68         check_error();
  69         // Intel/Mesa seems to have a broken glGenerateMipmap() for non-FBO textures, so do it here
  70         // instead of calling glGenerateMipmap().
  71         glTexParameteri(GL_TEXTURE_2D, GL_GENERATE_MIPMAP, needs_mipmaps);
  72         check_error();
  73         glTexImage2D(GL_TEXTURE_2D, 0, internal_format, width, height, 0, format, GL_UNSIGNED_BYTE, NULL);
  74         check_error();
  75         glPixelStorei(GL_UNPACK_ROW_LENGTH, 0);
  76         check_error();
  77
  78         needs_update = false;
  79         finalized = true;
  80 }
  81
  82 void FlatInput::set_gl_state(GLuint glsl_program_num, const std::string& prefix, unsigned *sampler_num)
  83 {
  84         glActiveTexture(GL_TEXTURE0 + *sampler_num);
  85         check_error();
  86         glBindTexture(GL_TEXTURE_2D, texture_num);
  87         check_error();
  88
  89         if (needs_update) {
  90                 // Copy the pixel data into the PBO.
  91                 glBindBuffer(GL_PIXEL_UNPACK_BUFFER_ARB, pbo);
  92                 check_error();
  93                 void *mapped_pbo = glMapBufferARB(GL_PIXEL_UNPACK_BUFFER_ARB, GL_WRITE_ONLY);
  94                 memcpy(mapped_pbo, pixel_data, pitch * height * bytes_per_pixel);
  95                 glUnmapBufferARB(GL_PIXEL_UNPACK_BUFFER_ARB);
  96                 check_error();
  97
  98                 // Re-upload the texture from the PBO.
  99                 glPixelStorei(GL_UNPACK_ROW_LENGTH, pitch);
 100                 check_error();
 101                 glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, width, height, format, GL_UNSIGNED_BYTE, BUFFER_OFFSET(0));
 102                 check_error();
 103                 glPixelStorei(GL_UNPACK_ROW_LENGTH, 0);
 104                 check_error();
 105                 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
 106                 check_error();
 107                 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
 108                 check_error();
 109                 glBindBuffer(GL_PIXEL_UNPACK_BUFFER_ARB, 0);
 110                 check_error();
 111
 112                 needs_update = false;
 113         }
 114
 115         // Bind it to a sampler.
 116         set_uniform_int(glsl_program_num, prefix, "tex", *sampler_num);
 117         ++*sampler_num;
 118 }
 119
 120 std::string FlatInput::output_fragment_shader()
 121 {
 122         return read_file("flat_input.frag");
 123 }