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, GLenum type, unsigned width, unsigned height)
   9         : image_format(image_format),
  10           pixel_format(pixel_format),
  11           type(type),
  12           needs_update(false),
  13           finalized(false),
  14           output_linear_gamma(false),
  15           needs_mipmaps(false),
  16           width(width),
  17           height(height),
  18           pitch(width)
  19 {
  20         assert(type == GL_FLOAT || type == GL_UNSIGNED_BYTE);
  21         register_int("output_linear_gamma", &output_linear_gamma);
  22         register_int("needs_mipmaps", &needs_mipmaps);
  23 }
  24
  25 void FlatInput::finalize()
  26 {
  27         // Translate the input format to OpenGL's enums.
  28         GLenum internal_format;
  29         if (type == GL_FLOAT) {
  30                 internal_format = GL_RGBA16F_ARB;
  31         } else if (output_linear_gamma) {
  32                 assert(type == GL_UNSIGNED_BYTE);
  33                 internal_format = GL_SRGB8;
  34         } else {
  35                 assert(type == GL_UNSIGNED_BYTE);
  36                 internal_format = GL_RGBA8;
  37         }
  38         if (pixel_format == FORMAT_RGB) {
  39                 format = GL_RGB;
  40                 bytes_per_pixel = 3;
  41         } else if (pixel_format == FORMAT_RGBA) {
  42                 format = GL_RGBA;
  43                 bytes_per_pixel = 4;
  44         } else if (pixel_format == FORMAT_BGR) {
  45                 format = GL_BGR;
  46                 bytes_per_pixel = 3;
  47         } else if (pixel_format == FORMAT_BGRA) {
  48                 format = GL_BGRA;
  49                 bytes_per_pixel = 4;
  50         } else if (pixel_format == FORMAT_GRAYSCALE) {
  51                 format = GL_LUMINANCE;
  52                 bytes_per_pixel = 1;
  53         } else {
  54                 assert(false);
  55         }
  56         if (type == GL_FLOAT) {
  57                 bytes_per_pixel *= sizeof(float);
  58         }
  59
  60         // Create PBO to hold the texture holding the input image, and then the texture itself.
  61         glGenBuffers(1, &pbo);
  62         check_error();
  63         glBindBuffer(GL_PIXEL_UNPACK_BUFFER_ARB, pbo);
  64         check_error();
  65         glBufferData(GL_PIXEL_UNPACK_BUFFER_ARB, pitch * height * bytes_per_pixel, NULL, GL_STREAM_DRAW);
  66         check_error();
  67         glBindBuffer(GL_PIXEL_UNPACK_BUFFER_ARB, 0);
  68         check_error();
  69
  70         glGenTextures(1, &texture_num);
  71         check_error();
  72         glBindTexture(GL_TEXTURE_2D, texture_num);
  73         check_error();
  74         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
  75         check_error();
  76         glPixelStorei(GL_UNPACK_ROW_LENGTH, pitch);
  77         check_error();
  78         // Intel/Mesa seems to have a broken glGenerateMipmap() for non-FBO textures, so do it here
  79         // instead of calling glGenerateMipmap().
  80         glTexParameteri(GL_TEXTURE_2D, GL_GENERATE_MIPMAP, needs_mipmaps);
  81         check_error();
  82         glTexImage2D(GL_TEXTURE_2D, 0, internal_format, width, height, 0, format, type, NULL);
  83         check_error();
  84         glPixelStorei(GL_UNPACK_ROW_LENGTH, 0);
  85         check_error();
  86
  87         needs_update = true;
  88         finalized = true;
  89 }
  90
  91 void FlatInput::set_gl_state(GLuint glsl_program_num, const std::string& prefix, unsigned *sampler_num)
  92 {
  93         glActiveTexture(GL_TEXTURE0 + *sampler_num);
  94         check_error();
  95         glBindTexture(GL_TEXTURE_2D, texture_num);
  96         check_error();
  97
  98         if (needs_update) {
  99                 // Copy the pixel data into the PBO.
 100                 glBindBuffer(GL_PIXEL_UNPACK_BUFFER_ARB, pbo);
 101                 check_error();
 102                 void *mapped_pbo = glMapBufferARB(GL_PIXEL_UNPACK_BUFFER_ARB, GL_WRITE_ONLY);
 103                 memcpy(mapped_pbo, pixel_data, pitch * height * bytes_per_pixel);
 104                 glUnmapBufferARB(GL_PIXEL_UNPACK_BUFFER_ARB);
 105                 check_error();
 106
 107                 // Re-upload the texture from the PBO.
 108                 glPixelStorei(GL_UNPACK_ROW_LENGTH, pitch);
 109                 check_error();
 110                 glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, width, height, format, GL_FLOAT, BUFFER_OFFSET(0));
 111                 check_error();
 112                 glPixelStorei(GL_UNPACK_ROW_LENGTH, 0);
 113                 check_error();
 114                 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
 115                 check_error();
 116                 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
 117                 check_error();
 118                 glBindBuffer(GL_PIXEL_UNPACK_BUFFER_ARB, 0);
 119                 check_error();
 120
 121                 needs_update = false;
 122         }
 123
 124         // Bind it to a sampler.
 125         set_uniform_int(glsl_program_num, prefix, "tex", *sampler_num);
 126         ++*sampler_num;
 127 }
 128
 129 std::string FlatInput::output_fragment_shader()
 130 {
 131         return read_file("flat_input.frag");
 132 }