glstuff

experiments with opengl2/ogles2/sdl
git clone http://frotz.net/git/glstuff.git
Log | Files | Refs

noisetoy.cc (3660B)

      1 #include <stdio.h>
      2 #include <stdlib.h>
      3 #include <string.h>
      4 
      5 #include "app.h"
      6 #include "util.h"
      7 #include "matrix.h"
      8 #include "program.h"
      9 #include "debugtext.h"
     10 
     11 #include <math.h>
     12 
     13 #include <SDL_keysym.h>
     14 
     15 class NoiseApp : public App {
     16 public:
     17 	NoiseApp();
     18 	int init(void);
     19 	int render(void);
     20 	void key(int code);
     21 private:
     22 	unsigned char *data;
     23 	int w, h;
     24 
     25 	int mode;
     26 
     27 	Program pgm;
     28 
     29 	GLuint tex0;
     30 	GLuint aVertex, aTexCoord;
     31 	GLuint uTexture;
     32 
     33 	float n;
     34 
     35 	DebugText dtxt;
     36 
     37 	float scale;
     38 	float offx,offy;
     39 };
     40 
     41 NoiseApp::NoiseApp() : App(), w(512), h(512) {
     42 	data = (unsigned char*) malloc(w * h);	
     43 	scale = 1.0;
     44 	offx = offy = 0;
     45 	n = 0;
     46 	mode = 0;
     47 }
     48 
     49 static const char *vsrc = R"(
     50 attribute vec2 aVertex;
     51 attribute vec2 aTexCoord;
     52 varying vec2 vTexCoord;
     53 void main() {
     54 	gl_Position = vec4(aVertex, 0.0, 1.0);
     55 	vTexCoord = aTexCoord;
     56 }
     57 )";
     58 
     59 static const char *fsrc = R"(
     60 uniform sampler2D uTexture;
     61 varying vec2 vTexCoord;
     62 void main() {
     63 	float c = texture2D(uTexture, vTexCoord).a;
     64 	gl_FragColor = vec4(c, c, c, 1.0);
     65 }
     66 )";
     67 
     68 int NoiseApp::init(void) {
     69 	if (pgm.compileStr(vsrc, fsrc))
     70 		return -1;
     71 
     72 	aVertex = pgm.getAttribID("aVertex");
     73 	aTexCoord = pgm.getAttribID("aTexCoord");
     74 	uTexture = pgm.getUniformID("uTexture");
     75 	glViewport(0, 0, width(), height());
     76 	glClearColor(0, 0, 0, 0);
     77 	glClearDepth(1.0f);
     78 	
     79 	glGenTextures(1, &tex0);
     80 
     81 	dtxt.init(32, 32);
     82 	return 0;
     83 }
     84 
     85 static GLfloat vtx_xy_uv[] = {
     86 	-1.0, -1.0, 0.0, 0.0,
     87 	-1.0,  1.0, 0.0, 1.0,
     88 	 1.0, -1.0, 1.0, 0.0,
     89 	 1.0,  1.0, 1.0, 1.0,
     90 };
     91 
     92 void NoiseApp::key(int code) {
     93 	switch (code) {
     94 	case SDLK_x:
     95 		fprintf(stderr,"saving...\n");
     96 		save_png_gray("out.png", data, w, h);
     97 		break;
     98 	case SDLK_m:
     99 		mode++;
    100 		if (mode == 4) mode = 0;
    101 		fprintf(stderr, "mode: %d\n", mode);
    102 		break;
    103 	}
    104 }
    105 
    106 int NoiseApp::render(void) {
    107 	int x, y;
    108 //	n += 0.01;
    109 
    110 	if (keydown(SDLK_w)) offy += 0.1;
    111 	if (keydown(SDLK_s)) offy -= 0.1;
    112 	if (keydown(SDLK_a)) offx -= 0.1;
    113 	if (keydown(SDLK_d)) offx += 0.1;
    114 
    115 	if (keydown(SDLK_r)) scale += 0.01;
    116 	if (keydown(SDLK_f)) scale -= 0.01;
    117 
    118 	for (y = 0; y < h; y++) {
    119 		for (x = 0; x < w; x++) {
    120 			float fy = float(y) / float(h) + offy;
    121 			float fx = float(x) / float(w) + offx;
    122 
    123 			fx *= scale;
    124 			fy *= scale;
    125 	
    126 			float sn = snoise(fx, fy) * 1.0;
    127 
    128 			switch (mode) {
    129 			case 2:
    130 				sn += snoise(fx*8.0,fy*8.0) * 0.0625;
    131 			case 1:
    132 				sn += snoise(fx*2.0,fy*2.0) * 0.25;
    133 				sn += snoise(fx*4.0,fy*4.0) * 0.125;
    134 				break;
    135 			case 3:
    136 				sn += snoise(fx*13.3,fy*9.2) * 0.65;
    137 				break;
    138 			}
    139 
    140 #if 1
    141 	if (sn < -1.0) sn = -1.0;
    142 	if (sn > 1.0) sn = 1.0;
    143 #endif
    144 
    145 			data[y*w+x] = 127.0 * (sn + 1.0);
    146 #if 0
    147 			if ((sn + (1.0-fy) * 1.0 ) > 0.75)
    148 				data[y*w+x] = 0xff;
    149 			else
    150 				data[y*w+x] = 0x00;
    151 #endif
    152 		}
    153 	}
    154 
    155 	glClear(GL_COLOR_BUFFER_BIT);
    156 
    157 	pgm.use();
    158 
    159 	glActiveTexture(GL_TEXTURE0);
    160 	glBindTexture(GL_TEXTURE_2D, tex0);
    161 	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
    162 	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
    163 	glTexImage2D(GL_TEXTURE_2D, 0, GL_ALPHA, w, h, 0, GL_ALPHA, GL_UNSIGNED_BYTE, data);
    164 
    165 	glUniform1i(uTexture, 0);
    166 
    167 	glBindBuffer(GL_ARRAY_BUFFER, 0);
    168 	glVertexAttribPointer(aVertex, 2, GL_FLOAT, GL_FALSE, 4*4, vtx_xy_uv);
    169 	glVertexAttribPointer(aTexCoord, 2, GL_FLOAT, GL_FALSE, 4*4, vtx_xy_uv + 2);
    170 
    171 	glEnableVertexAttribArray(aVertex);
    172 	glEnableVertexAttribArray(aTexCoord);
    173 	glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
    174 	glDisableVertexAttribArray(aVertex);
    175 	glDisableVertexAttribArray(aTexCoord);
    176 
    177 	dtxt.clear();
    178 	dtxt.printf("%d> %f %f %f\n", mode, offx, offy, scale);
    179 	dtxt.render();
    180 	return 0;
    181 }
    182 
    183 int main(int argc, char **argv) {
    184 	NoiseApp app;
    185 	app.setSize(512, 512);
    186 	app.setOptions(argc, argv);
    187 	return app.run();
    188 }