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           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;
  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) {
  56                 format = GL_RGBA;
  57                 bytes_per_pixel = 4;
  58         } else if (pixel_format == FORMAT_BGR) {
  59                 format = GL_BGR;
  60                 bytes_per_pixel = 3;
  61         } else if (pixel_format == FORMAT_BGRA) {
  62                 format = GL_BGRA;
  63                 bytes_per_pixel = 4;
  64         } else if (pixel_format == FORMAT_GRAYSCALE) {
  65                 format = GL_LUMINANCE;
  66                 bytes_per_pixel = 1;
  67         } else {
  68                 assert(false);
  69         }
  70         if (type == GL_FLOAT) {
  71                 bytes_per_pixel *= sizeof(float);
  72         }
  73
  74         // Create PBO to hold the texture holding the input image, and then the texture itself.
  75         glGenBuffers(1, &pbo);
  76         check_error();
  77         glBindBuffer(GL_PIXEL_UNPACK_BUFFER_ARB, pbo);
  78         check_error();
  79         glBufferData(GL_PIXEL_UNPACK_BUFFER_ARB, pitch * height * bytes_per_pixel, NULL, GL_STREAM_DRAW);
  80         check_error();
  81         glBindBuffer(GL_PIXEL_UNPACK_BUFFER_ARB, 0);
  82         check_error();
  83
  84         glGenTextures(1, &texture_num);
  85         check_error();
  86         glBindTexture(GL_TEXTURE_2D, texture_num);
  87         check_error();
  88         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, needs_mipmaps ? GL_LINEAR_MIPMAP_NEAREST : GL_LINEAR);
  89         check_error();
  90         glPixelStorei(GL_UNPACK_ROW_LENGTH, pitch);
  91         check_error();
  92         // Intel/Mesa seems to have a broken glGenerateMipmap() for non-FBO textures, so do it here
  93         // instead of calling glGenerateMipmap().
  94         glTexParameteri(GL_TEXTURE_2D, GL_GENERATE_MIPMAP, needs_mipmaps ? GL_TRUE : GL_FALSE);
  95         check_error();
  96         glTexImage2D(GL_TEXTURE_2D, 0, internal_format, width, height, 0, format, type, NULL);
  97         check_error();
  98         glPixelStorei(GL_UNPACK_ROW_LENGTH, 0);
  99         check_error();
 100
 101         needs_update = true;
 102         finalized = true;
 103 }
 104
 105 void FlatInput::set_gl_state(GLuint glsl_program_num, const std::string& prefix, unsigned *sampler_num)
 106 {
 107         glActiveTexture(GL_TEXTURE0 + *sampler_num);
 108         check_error();
 109         glBindTexture(GL_TEXTURE_2D, texture_num);
 110         check_error();
 111
 112         if (needs_update) {
 113                 // Copy the pixel data into the PBO.
 114                 glBindBuffer(GL_PIXEL_UNPACK_BUFFER_ARB, pbo);
 115                 check_error();
 116                 void *mapped_pbo = glMapBufferARB(GL_PIXEL_UNPACK_BUFFER_ARB, GL_WRITE_ONLY);
 117                 memcpy(mapped_pbo, pixel_data, pitch * height * bytes_per_pixel);
 118                 glUnmapBufferARB(GL_PIXEL_UNPACK_BUFFER_ARB);
 119                 check_error();
 120
 121                 // Re-upload the texture from the PBO.
 122                 glPixelStorei(GL_UNPACK_ROW_LENGTH, pitch);
 123                 check_error();
 124                 glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, width, height, format, type, BUFFER_OFFSET(0));
 125                 check_error();
 126                 glPixelStorei(GL_UNPACK_ROW_LENGTH, 0);
 127                 check_error();
 128                 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
 129                 check_error();
 130                 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
 131                 check_error();
 132                 glBindBuffer(GL_PIXEL_UNPACK_BUFFER_ARB, 0);
 133                 check_error();
 134
 135                 needs_update = false;
 136         }
 137
 138         // Bind it to a sampler.
 139         set_uniform_int(glsl_program_num, prefix, "tex", *sampler_num);
 140         ++*sampler_num;
 141 }
 142
 143 std::string FlatInput::output_fragment_shader()
 144 {
 145         return read_file("flat_input.frag");
 146 }