shader.c

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// mightymandel -- GPU-based Mandelbrot Set explorer
// Copyright (C) 2012,2013,2014,2015 Claude Heiland-Allen
// License GPL3+ http://www.gnu.org/licenses/gpl.html

#include <stdlib.h>

#include "shader.h"
#include "logging.h"
#include "mightymandel.h"

extern const char *fp32_preamble; 
extern const char *fp64_preamble; 
extern const char *fp32_complex;  
extern const char *fp64_complex;  
extern const char *config;        

void debug_program(GLuint program, const char *name) {
  if (program) {
    GLint linked = GL_FALSE;
    glGetProgramiv(program, GL_LINK_STATUS, &linked);D;
    if (linked != GL_TRUE) {
      log_message(LOG_ERROR, "%s: OpenGL shader program link failed\n", name);
    }
    int length;
    glGetProgramiv(program, GL_INFO_LOG_LENGTH, &length);D;
    char *buffer = (char *) malloc(length + 1);
    glGetProgramInfoLog(program, length, NULL, buffer);D;
    buffer[length] = 0;
    if (buffer[0]) {
      log_message(LOG_WARN, "%s: shader compile log\n", name);
      if (LOG_WARN <= log_level) {
        fprintf(log_target, "%s\n", buffer);
      }
    }
    free(buffer);
  } else {
    log_message(LOG_ERROR, "%s: OpenGL program creation failed\n", name);
  }
}

void compile_shader(GLint program, GLenum type, const GLchar *source) {
  const GLchar *fp32_sources[5] = { fp32_preamble, config, DE ? "#define DE 1\n" : "", fp32_complex,               source };
  const GLchar *fp64_sources[6] = { fp64_preamble, config, DE ? "#define DE 1\n" : "", fp32_complex, fp64_complex, source };
  GLuint shader = glCreateShader(type);D;
  glShaderSource(shader, FP64 ? 6 : 5, FP64 ? fp64_sources : fp32_sources, NULL);D;
  glCompileShader(shader);D;
  glAttachShader(program, shader);D;
  glDeleteShader(shader);D;
}

GLint compile_program_tf(const char *name, const GLchar *vert, const GLchar *geom, const GLchar *frag, int nvaryings, const GLchar **varyings) {
  GLint program = glCreateProgram();D;
  if (vert) { compile_shader(program, GL_VERTEX_SHADER  , vert); }
  if (geom) { compile_shader(program, GL_GEOMETRY_SHADER, geom); }
  if (frag) { compile_shader(program, GL_FRAGMENT_SHADER, frag); }
  if (nvaryings) {
    glTransformFeedbackVaryings(program, nvaryings, varyings, GL_INTERLEAVED_ATTRIBS);D;
  }
  glLinkProgram(program);D;
  debug_program(program, name);
  return program;
}

GLint compile_program(const char *name, const GLchar *vert, const GLchar *geom, const GLchar *frag) {
  return compile_program_tf(name, vert, geom, frag, 0, 0);
}