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           pixel_data(NULL)
  22 {
  23         assert(type == GL_FLOAT || type == GL_UNSIGNED_BYTE);
  24         register_int("output_linear_gamma", &output_linear_gamma);
  25         register_int("needs_mipmaps", &needs_mipmaps);
  26 }
  27
  28 FlatInput::~FlatInput()
  29 {
  30         if (pbo != 0) {
  31                 glDeleteBuffers(1, &pbo);
  32                 check_error();
  33         }
  34         if (texture_num != 0) {
  35                 glDeleteTextures(1, &texture_num);
  36                 check_error();
  37         }
  38 }
  39
  40 void FlatInput::finalize()
  41 {
  42         // Translate the input format to OpenGL's enums.
  43         GLenum internal_format;
  44         if (type == GL_FLOAT) {
  45                 internal_format = GL_RGBA16F_ARB;
  46         } else if (output_linear_gamma) {
  47                 assert(type == GL_UNSIGNED_BYTE);
  48                 internal_format = GL_SRGB8_ALPHA8;
  49         } else {
  50                 assert(type == GL_UNSIGNED_BYTE);
  51                 internal_format = GL_RGBA8;
  52         }
  53         if (pixel_format == FORMAT_RGB) {
  54                 format = GL_RGB;
  55                 bytes_per_pixel = 3;
  56         } else if (pixel_format == FORMAT_RGBA_PREMULTIPLIED_ALPHA ||
  57                    pixel_format == FORMAT_RGBA_POSTMULTIPLIED_ALPHA) {
  58                 format = GL_RGBA;
  59                 bytes_per_pixel = 4;
  60         } else if (pixel_format == FORMAT_BGR) {
  61                 format = GL_BGR;
  62                 bytes_per_pixel = 3;
  63         } else if (pixel_format == FORMAT_BGRA_PREMULTIPLIED_ALPHA ||
  64                    pixel_format == FORMAT_BGRA_POSTMULTIPLIED_ALPHA) {
  65                 format = GL_BGRA;
  66                 bytes_per_pixel = 4;
  67         } else if (pixel_format == FORMAT_GRAYSCALE) {
  68                 format = GL_LUMINANCE;
  69                 bytes_per_pixel = 1;
  70         } else {
  71                 assert(false);
  72         }
  73         if (type == GL_FLOAT) {
  74                 bytes_per_pixel *= sizeof(float);
  75         }
  76
  77         // Create PBO to hold the texture holding the input image, and then the texture itself.
  78         glGenBuffers(1, &pbo);
  79         check_error();
  80         glBindBuffer(GL_PIXEL_UNPACK_BUFFER_ARB, pbo);
  81         check_error();
  82         glBufferData(GL_PIXEL_UNPACK_BUFFER_ARB, pitch * height * bytes_per_pixel, NULL, GL_STREAM_DRAW);
  83         check_error();
  84         glBindBuffer(GL_PIXEL_UNPACK_BUFFER_ARB, 0);
  85         check_error();
  86
  87         glGenTextures(1, &texture_num);
  88         check_error();
  89         glBindTexture(GL_TEXTURE_2D, texture_num);
  90         check_error();
  91         glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
  92         check_error();
  93         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, needs_mipmaps ? GL_LINEAR_MIPMAP_NEAREST : GL_LINEAR);
  94         check_error();
  95         glPixelStorei(GL_UNPACK_ROW_LENGTH, pitch);
  96         check_error();
  97         // Intel/Mesa seems to have a broken glGenerateMipmap() for non-FBO textures, so do it here
  98         // instead of calling glGenerateMipmap().
  99         glTexParameteri(GL_TEXTURE_2D, GL_GENERATE_MIPMAP, needs_mipmaps ? GL_TRUE : GL_FALSE);
 100         check_error();
 101         glTexImage2D(GL_TEXTURE_2D, 0, internal_format, width, height, 0, format, type, NULL);
 102         check_error();
 103         glPixelStorei(GL_UNPACK_ROW_LENGTH, 0);
 104         check_error();
 105
 106         needs_update = true;
 107         finalized = true;
 108 }
 109
 110 void FlatInput::set_gl_state(GLuint glsl_program_num, const std::string& prefix, unsigned *sampler_num)
 111 {
 112         glActiveTexture(GL_TEXTURE0 + *sampler_num);
 113         check_error();
 114         glBindTexture(GL_TEXTURE_2D, texture_num);
 115         check_error();
 116
 117         if (needs_update) {
 118                 // Copy the pixel data into the PBO.
 119                 glBindBuffer(GL_PIXEL_UNPACK_BUFFER_ARB, pbo);
 120                 check_error();
 121                 void *mapped_pbo = glMapBufferARB(GL_PIXEL_UNPACK_BUFFER_ARB, GL_WRITE_ONLY);
 122                 memcpy(mapped_pbo, pixel_data, pitch * height * bytes_per_pixel);
 123                 glUnmapBufferARB(GL_PIXEL_UNPACK_BUFFER_ARB);
 124                 check_error();
 125
 126                 // Re-upload the texture from the PBO.
 127                 glPixelStorei(GL_UNPACK_ROW_LENGTH, pitch);
 128                 check_error();
 129                 glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, width, height, format, type, BUFFER_OFFSET(0));
 130                 check_error();
 131                 glPixelStorei(GL_UNPACK_ROW_LENGTH, 0);
 132                 check_error();
 133                 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
 134                 check_error();
 135                 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
 136                 check_error();
 137                 glBindBuffer(GL_PIXEL_UNPACK_BUFFER_ARB, 0);
 138                 check_error();
 139
 140                 needs_update = false;
 141         }
 142
 143         // Bind it to a sampler.
 144         set_uniform_int(glsl_program_num, prefix, "tex", *sampler_num);
 145         ++*sampler_num;
 146 }
 147
 148 std::string FlatInput::output_fragment_shader()
 149 {
 150         return read_file("flat_input.frag");
 151 }