volmetrics
diff src/sdr.cc @ 22:4e120dcd55ec
added shaders that just draw
author | Eleni Maria Stea <elene.mst@gmail.com> |
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date | Thu, 24 Apr 2014 20:47:48 +0300 |
parents | |
children | df4a277adb82 |
line diff
1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000 1.2 +++ b/src/sdr.cc Thu Apr 24 20:47:48 2014 +0300 1.3 @@ -0,0 +1,104 @@ 1.4 +#include <GL/glew.h> 1.5 +#include <GL/gl.h> 1.6 + 1.7 +#include <errno.h> 1.8 +#include <stdio.h> 1.9 +#include <stdlib.h> 1.10 +#include <string.h> 1.11 + 1.12 +#include "sdr.h" 1.13 + 1.14 +char* sdr_load(const char* fname) 1.15 +{ 1.16 + if(!fname) { 1.17 + return 0; 1.18 + } 1.19 + 1.20 + FILE *fp; 1.21 + int ctr = 0; 1.22 + 1.23 + if(!(fp = fopen(fname, "rb"))) { 1.24 + fprintf(stderr, "Failed to open file %s: %s\n", fname, strerror(errno)); 1.25 + return 0; 1.26 + } 1.27 + fseek(fp, 0, SEEK_END); 1.28 + ctr = ftell(fp); 1.29 + rewind(fp); 1.30 + 1.31 + char *glsl; 1.32 + if(!(glsl = (char*) malloc(ctr + 1))) { 1.33 + perror("Failed to allocate memory"); 1.34 + return 0; 1.35 + } 1.36 + fread(glsl, 1, ctr, fp); 1.37 + fclose(fp); 1.38 + 1.39 + glsl[ctr] = 0; 1.40 + 1.41 + return glsl; 1.42 +} 1.43 + 1.44 +bool sdr_compile(unsigned int sdr) 1.45 +{ 1.46 + int status, loglen; 1.47 + char infolog[512]; 1.48 + 1.49 + glCompileShader(sdr); 1.50 + glGetShaderiv(sdr, GL_COMPILE_STATUS, &status); 1.51 + glGetShaderInfoLog(sdr, sizeof infolog, &loglen, infolog); 1.52 + if(status == GL_FALSE) { 1.53 + fprintf(stderr, "Failed to compile shader: %s\n", infolog); 1.54 + return false; 1.55 + } else if(loglen) { 1.56 + fprintf(stderr, "%s\n", infolog); 1.57 + } 1.58 + return true; 1.59 +} 1.60 + 1.61 +unsigned int sdr_getprog(const char* vfname, const char* ffname) 1.62 +{ 1.63 + char *vsdr_glsl = NULL; 1.64 + char *fsdr_glsl = NULL; 1.65 + 1.66 + GLuint vsdr; GLuint fsdr; 1.67 + vsdr = glCreateShader(GL_VERTEX_SHADER); 1.68 + fsdr = glCreateShader(GL_FRAGMENT_SHADER); 1.69 + 1.70 + if(!(vsdr_glsl = sdr_load(vfname))) 1.71 + return 0; 1.72 + if(!(fsdr_glsl = sdr_load(ffname))) 1.73 + return 0; 1.74 + 1.75 + glShaderSource(vsdr, 1, (const GLchar**)&vsdr_glsl, NULL); 1.76 + glShaderSource(fsdr, 1, (const GLchar**)&fsdr_glsl, NULL); 1.77 + 1.78 + free(vsdr_glsl); 1.79 + free(fsdr_glsl); 1.80 + 1.81 + if(!sdr_compile(vsdr)) { 1.82 + fprintf(stderr, "Shader %s failed to compile.\n", vfname); 1.83 + return 0; 1.84 + } 1.85 + if(!sdr_compile(fsdr)) { 1.86 + fprintf(stderr, "Shader %s failed to compile.\n", ffname); 1.87 + return 0; 1.88 + } 1.89 + 1.90 + unsigned int sprog; 1.91 + int status, loglen; 1.92 + char infolog[512]; 1.93 + 1.94 + sprog = glCreateProgram(); 1.95 + glAttachShader(sprog, vsdr); 1.96 + glAttachShader(sprog, fsdr); 1.97 + glLinkProgram(sprog); 1.98 + glGetProgramiv(sprog, GL_LINK_STATUS, &status); 1.99 + glGetProgramInfoLog(sprog, sizeof infolog, &loglen, infolog); 1.100 + if(status == GL_FALSE) { 1.101 + fprintf(stderr, "Error while linking shader program:\n%s\n", infolog); 1.102 + return 0; 1.103 + } else if(loglen) { 1.104 + fprintf(stderr, "%s\n", infolog); 1.105 + } 1.106 + return sprog; 1.107 +}