path: root/libvo/gl_common.c

/**
 * \file gl_common.c
 * \brief OpenGL helper functions used by vo_gl.c and vo_gl2.c
 *
 * Common OpenGL routines.
 * Copyleft (C) Reimar Döffinger <Reimar.Doeffinger@stud.uni-karlsruhe.de>, 2005
 * Licensend under the GNU GPL v2 or later.
 * Special thanks go to the xine team and Matthias Hopf, whose video_out_opengl.c
 * gave me lots of good ideas.
 */
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include <math.h>
#include "gl_common.h"

/**
 * \defgroup glextfunctions OpenGL extension functions
 *
 * the pointers to these functions are acquired when the OpenGL
 * context is created
 * \{
 */
void (APIENTRY *GenBuffers)(GLsizei, GLuint *);
void (APIENTRY *DeleteBuffers)(GLsizei, const GLuint *);
void (APIENTRY *BindBuffer)(GLenum, GLuint);
GLvoid* (APIENTRY *MapBuffer)(GLenum, GLenum); 
GLboolean (APIENTRY *UnmapBuffer)(GLenum);
void (APIENTRY *BufferData)(GLenum, intptr_t, const GLvoid *, GLenum);
void (APIENTRY *CombinerParameterfv)(GLenum, const GLfloat *);
void (APIENTRY *CombinerParameteri)(GLenum, GLint);
void (APIENTRY *CombinerInput)(GLenum, GLenum, GLenum, GLenum, GLenum,
                               GLenum);
void (APIENTRY *CombinerOutput)(GLenum, GLenum, GLenum, GLenum, GLenum,
                                GLenum, GLenum, GLboolean, GLboolean,
                                GLboolean);
void (APIENTRY *BeginFragmentShader)(void);
void (APIENTRY *EndFragmentShader)(void);
void (APIENTRY *SampleMap)(GLuint, GLuint, GLenum);
void (APIENTRY *ColorFragmentOp2)(GLenum, GLuint, GLuint, GLuint, GLuint,
                                  GLuint, GLuint, GLuint, GLuint, GLuint);
void (APIENTRY *ColorFragmentOp3)(GLenum, GLuint, GLuint, GLuint, GLuint,
                                  GLuint, GLuint, GLuint, GLuint, GLuint,
                                  GLuint, GLuint, GLuint);
void (APIENTRY *SetFragmentShaderConstant)(GLuint, const GLfloat *);
void (APIENTRY *ActiveTexture)(GLenum);
void (APIENTRY *BindTexture)(GLenum, GLuint);
void (APIENTRY *MultiTexCoord2f)(GLenum, GLfloat, GLfloat);
void (APIENTRY *GenPrograms)(GLsizei, GLuint *);
void (APIENTRY *DeletePrograms)(GLsizei, const GLuint *);
void (APIENTRY *BindProgram)(GLenum, GLuint);
void (APIENTRY *ProgramString)(GLenum, GLenum, GLsizei, const GLvoid *);
void (APIENTRY *GetProgramiv)(GLenum, GLenum, GLint *);
void (APIENTRY *ProgramEnvParameter4f)(GLenum, GLuint, GLfloat, GLfloat,
                                       GLfloat, GLfloat);
int (APIENTRY *SwapInterval)(int);
void (APIENTRY *TexImage3D)(GLenum, GLint, GLenum, GLsizei, GLsizei, GLsizei,
                            GLint, GLenum, GLenum, const GLvoid *);
/** \} */ // end of glextfunctions group

//! \defgroup glgeneral OpenGL general helper functions

//! \defgroup glcontext OpenGL context management helper functions

//! \defgroup gltexture OpenGL texture handling helper functions

//! \defgroup glconversion OpenGL conversion helper functions

static GLint hqtexfmt;

/**
 * \brief adjusts the GL_UNPACK_ALIGNMENT to fit the stride.
 * \param stride number of bytes per line for which alignment should fit.
 * \ingroup glgeneral
 */
void glAdjustAlignment(int stride) {
  GLint gl_alignment;
  if (stride % 8 == 0)
    gl_alignment=8;
  else if (stride % 4 == 0)
    gl_alignment=4;
  else if (stride % 2 == 0)
    gl_alignment=2;
  else
    gl_alignment=1;
  glPixelStorei (GL_UNPACK_ALIGNMENT, gl_alignment);
}

struct gl_name_map_struct {
  GLint value;
  const char *name;
};

#undef MAP
#define MAP(a) {a, #a}
//! mapping table for the glValName function
static const struct gl_name_map_struct gl_name_map[] = {
  // internal format
  MAP(GL_R3_G3_B2), MAP(GL_RGB4), MAP(GL_RGB5), MAP(GL_RGB8),
  MAP(GL_RGB10), MAP(GL_RGB12), MAP(GL_RGB16), MAP(GL_RGBA2),
  MAP(GL_RGBA4), MAP(GL_RGB5_A1), MAP(GL_RGBA8), MAP(GL_RGB10_A2),
  MAP(GL_RGBA12), MAP(GL_RGBA16), MAP(GL_LUMINANCE8),

  // format
  MAP(GL_RGB), MAP(GL_RGBA), MAP(GL_RED), MAP(GL_GREEN), MAP(GL_BLUE),
  MAP(GL_ALPHA), MAP(GL_LUMINANCE), MAP(GL_LUMINANCE_ALPHA),
  MAP(GL_COLOR_INDEX),
  // rest 1.2 only
  MAP(GL_BGR), MAP(GL_BGRA),

  //type
  MAP(GL_BYTE), MAP(GL_UNSIGNED_BYTE), MAP(GL_SHORT), MAP(GL_UNSIGNED_SHORT),
  MAP(GL_INT), MAP(GL_UNSIGNED_INT), MAP(GL_FLOAT), MAP(GL_DOUBLE),
  MAP(GL_2_BYTES), MAP(GL_3_BYTES), MAP(GL_4_BYTES),
  // rest 1.2 only
  MAP(GL_UNSIGNED_BYTE_3_3_2), MAP(GL_UNSIGNED_BYTE_2_3_3_REV),
  MAP(GL_UNSIGNED_SHORT_5_6_5), MAP(GL_UNSIGNED_SHORT_5_6_5_REV),
  MAP(GL_UNSIGNED_SHORT_4_4_4_4), MAP(GL_UNSIGNED_SHORT_4_4_4_4_REV),
  MAP(GL_UNSIGNED_SHORT_5_5_5_1), MAP(GL_UNSIGNED_SHORT_1_5_5_5_REV),
  MAP(GL_UNSIGNED_INT_8_8_8_8), MAP(GL_UNSIGNED_INT_8_8_8_8_REV),
  MAP(GL_UNSIGNED_INT_10_10_10_2), MAP(GL_UNSIGNED_INT_2_10_10_10_REV),
  {0, 0}
};
#undef MAP

/**
 * \brief return the name of an OpenGL constant
 * \param value the constant
 * \return name of the constant or "Unknown format!"
 * \ingroup glgeneral
 */
const char *glValName(GLint value)
{
  int i = 0;

  while (gl_name_map[i].name) {
    if (gl_name_map[i].value == value)
      return gl_name_map[i].name;
    i++;
  }
  return "Unknown format!";
}

//! always return this format as internal texture format in glFindFormat
#define TEXTUREFORMAT_ALWAYS GL_RGB8
#undef TEXTUREFORMAT_ALWAYS

/**
 * \brief find the OpenGL settings coresponding to format.
 *
 * All parameters may be NULL.
 * \param fmt MPlayer format to analyze.
 * \param bpp [OUT] bits per pixel of that format.
 * \param gl_texfmt [OUT] internal texture format that fits the
 * image format, not necessarily the best for performance.
 * \param gl_format [OUT] OpenGL format for this image format.
 * \param gl_type [OUT] OpenGL type for this image format.
 * \return 1 if format is supported by OpenGL, 0 if not.
 * \ingroup gltexture
 */
int glFindFormat(uint32_t fmt, int *bpp, GLint *gl_texfmt,
                  GLenum *gl_format, GLenum *gl_type)
{
  int supported = 1;
  int dummy1;
  GLenum dummy2;
  GLint dummy3;
  if (bpp == NULL) bpp = &dummy1;
  if (gl_texfmt == NULL) gl_texfmt = &dummy3;
  if (gl_format == NULL) gl_format = &dummy2;
  if (gl_type == NULL) gl_type = &dummy2;
  
  *bpp = IMGFMT_IS_BGR(fmt)?IMGFMT_BGR_DEPTH(fmt):IMGFMT_RGB_DEPTH(fmt);
  *gl_texfmt = 3;