_plzpart/opengl.c

   1 #include <stdio.h>
   2 #include <string.h>
   3 #include <stdlib.h>
   4 #include <math.h>
   5 #include <GLES2/gl2.h>
   6 #include "u2gl.h"
   7 #include "opengl.h"
   8
   9 static int view_width;
  10 static int view_height;
  11
  12 static struct u2gl_program bg_program;
  13
  14 float obj[9];
  15
  16 float bg_obj[12] = {
  17         0.0f, 0.0f, 0.0f,
  18         320.0f, 0.0f, 0.0f,
  19         0.0f, 200.0f, 0.0f,
  20         320.0f, 200.0f, 0.0f
  21 };
  22
  23 static const char vertex_shader_texture[] =
  24 "uniform mat4 pMatrix;\n"
  25 "uniform mat4 uMatrix;\n"
  26 "attribute vec4 aPosition;\n"
  27 "varying vec3 vPosition;\n"
  28 "attribute vec2 aTexPosition;\n"
  29 "varying vec2 vTexPosition;\n"
  30 "\n"
  31 "void main() {\n"
  32 "    mat4 Matrix = pMatrix * uMatrix;\n"
  33 "    vec4 position = Matrix * aPosition;\n"
  34 "    gl_Position = position;\n"
  35 "    vTexPosition = aTexPosition;\n"
  36 "    vPosition = vec3(position);\n"
  37 "}\n";
  38
  39 static const char fragment_shader_texture[] =
  40 "precision mediump float;\n"
  41 "uniform sampler2D uTexture;\n"
  42 "uniform vec4 uColor;\n"
  43 "varying vec3 vPosition;\n"
  44 "varying vec2 vTexPosition;\n"
  45 "\n"
  46 "void main() {\n"
  47 "    gl_FragColor = texture2D(uTexture, vTexPosition);\n"
  48 "}\n";
  49
  50
  51 int uTime_location;
  52 int uPos_location;
  53 int uTexPos_location;
  54 int uRadius_location;
  55 int uLensTex_location;
  56 int uRotTex_location;
  57
  58 static float tex_coords[] = {
  59         0.0f, 1.0f,
  60         1.0f, 1.0f,
  61         0.0f, 0.0f,
  62         1.0f, 0.0f
  63 };
  64
  65 static float color[256][4];
  66
  67 unsigned char *image;
  68
  69
  70 #define CC 32
  71
  72 void setrgb(int c, int r, int g, int b)
  73 {
  74         float alpha = 0.5f;
  75
  76         color[c][0] = (float)r / CC;
  77         color[c][1] = (float)g / CC;
  78         color[c][2] = (float)b / CC;
  79         color[c][3] = alpha;
  80 }
  81
  82 void getrgb(int c, char *p)
  83 {
  84         p[0] = color[c][0] * CC;
  85         p[1] = color[c][1] * CC;
  86         p[2] = color[c][2] * CC;
  87 }
  88
  89 void draw_bg()
  90 {
  91         //glActiveTexture(GL_TEXTURE0);
  92         glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, 320, 400, GL_RGB,
  93                                         GL_UNSIGNED_BYTE, image);
  94         glUseProgram(bg_program.program);
  95         u2gl_draw_textured_triangle_strip(&bg_program, bg_obj, 4);
  96 }
  97
  98 static void init_texture()
  99 {
 100         GLuint tex[3];
 101
 102         u2gl_set_tex_coords(tex_coords);
 103
 104         glGenTextures(1, tex);
 105         glActiveTexture(GL_TEXTURE0);
 106         glBindTexture(GL_TEXTURE_2D, tex[0]);
 107         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
 108         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
 109         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
 110         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
 111
 112         image = calloc(3, 320 * 400);
 113
 114         glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, 320, 400, 0, GL_RGB,
 115                                 GL_UNSIGNED_BYTE, image);
 116         glGenerateMipmap(GL_TEXTURE_2D);
 117         u2gl_check_error("init_texture 1");
 118 }
 119
 120
 121 int init_opengl()
 122 {
 123         GLuint v, f;
 124
 125         view_width = 320;
 126         view_height = 200;
 127
 128         v = u2gl_compile_vertex_shader(vertex_shader_texture);
 129         f = u2gl_compile_fragment_shader(fragment_shader_texture);
 130         u2gl_create_program(&bg_program, f, v);
 131         u2gl_check_error("create program bg");
 132
 133         glDisable(GL_DEPTH_TEST);
 134         glEnable(GL_BLEND);
 135
 136         //glBlendFunc(GL_SRC_ALPHA, GL_ONE);
 137         glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
 138
 139         glClearColor(.0, .0, .0, 0);
 140         u2gl_check_error("init_opengl");
 141
 142         init_texture();
 143         u2gl_check_error("init_texture");
 144
 145         u2gl_projection(0, view_width, 0, view_height, &bg_program);
 146
 147         return 0;
 148 }
 149
 150 void clear_screen()
 151 {
 152         glClear(GL_COLOR_BUFFER_BIT);
 153 }