glstuff

commit 50b0912c70948e78923e3cc958f349e38b1dd6ae
parent 37d8023091e6d68b88854741fa4648c10422d3e7
Author: Brian Swetland <swetland@frotz.net>
Date:   Tue, 29 Jan 2013 22:47:00 -0800

noisetoy - scroll around some 2d noise

Diffstat:
M
Makefile
 | 
6
++++--
A
noisetoy.cc
 | 
166
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

2 files changed, 170 insertions(+), 2 deletions(-)
diff --git a/Makefile b/Makefile
@@ -1,4 +1,6 @@
 
+APPS := test1 test2 test3 test4 test5 noisetoy
+
 SDLCFG := sdl-config
 #SDLCFG := /work/sdl/bin/sdl2-config
 
@@ -7,6 +9,7 @@ SDLLIBS := $(shell $(SDLCFG) --libs)
 
 CFLAGS := $(SDLFLAGS) -DWITH_SDL2=0 -Wall -g -O2
 CFLAGS += -ffunction-sections -fdata-sections
+CFLAGS += -std=c++0x
 
 LFLAGS := -static-libstdc++
 LFLAGS += -Wl,-gc-sections
@@ -23,13 +26,12 @@ LIBOBJS += loadobj.o
 LIBOBJS += matrix.o program.o
 LIBOBJS += debugtext.o
 LIBOBJS += sdlglue.o
+LIBOBJS += simplexnoise.o
 
 stuff.a: $(LIBOBJS)
 	rm -f stuff.a
 	ar cr stuff.a $(LIBOBJS)
 
-APPS := test1 test2 test3 test4 test5 
-
 define build-test
 $1: $1.o stuff.a
 	$(CXX) $(LFLAGS) -o $1 $1.o $(COMMONOBJS) $(LIBS)
diff --git a/noisetoy.cc b/noisetoy.cc
@@ -0,0 +1,166 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "app.h"
+#include "util.h"
+#include "matrix.h"
+#include "program.h"
+#include "debugtext.h"
+
+#include <math.h>
+
+#include <SDL_keysym.h>
+
+class NoiseApp : public App {
+public:
+	NoiseApp();
+	int init(void);
+	int render(void);
+private:
+	unsigned char *data;
+	int w, h;
+
+	Program pgm;
+
+	GLuint tex0;
+	GLuint aVertex, aTexCoord;
+	GLuint uTexture;
+
+	float n;
+
+	DebugText dtxt;
+
+	float scale;
+	float offx,offy;
+};
+
+NoiseApp::NoiseApp() : App(), w(512), h(512) {
+	data = (unsigned char*) malloc(w * h);	
+	scale = 1.0;
+	offx = offy = 0;
+	n = 0;
+}
+
+static const char *vsrc = R"(
+attribute vec2 aVertex;
+attribute vec2 aTexCoord;
+varying vec2 vTexCoord;
+void main() {
+	gl_Position = vec4(aVertex, 0.0, 1.0);
+	vTexCoord = aTexCoord;
+}
+)";
+
+static const char *fsrc = R"(
+uniform sampler2D uTexture;
+varying vec2 vTexCoord;
+void main() {
+	float c = texture2D(uTexture, vTexCoord).a;
+	gl_FragColor = vec4(c, c, c, 1.0);
+}
+)";
+
+int NoiseApp::init(void) {
+	if (pgm.compileStr(vsrc, fsrc))
+		return -1;
+
+	aVertex = pgm.getAttribID("aVertex");
+	aTexCoord = pgm.getAttribID("aTexCoord");
+	uTexture = pgm.getUniformID("uTexture");
+	glViewport(0, 0, width(), height());
+	glClearColor(0, 0, 0, 0);
+	glClearDepth(1.0f);
+	
+	glGenTextures(1, &tex0);
+
+	dtxt.init(32, 32);
+	return 0;
+}
+
+static GLfloat vtx_xy_uv[] = {
+	-1.0, -1.0, 0.0, 0.0,
+	-1.0,  1.0, 0.0, 1.0,
+	 1.0, -1.0, 1.0, 0.0,
+	 1.0,  1.0, 1.0, 1.0,
+};
+
+int NoiseApp::render(void) {
+	int x, y;
+//	n += 0.01;
+
+	if (keydown(SDLK_w)) offy += 0.1;
+	if (keydown(SDLK_s)) offy -= 0.1;
+	if (keydown(SDLK_a)) offx -= 0.1;
+	if (keydown(SDLK_d)) offx += 0.1;
+
+	if (keydown(SDLK_r)) scale += 0.1;
+	if (keydown(SDLK_f)) scale -= 0.1;
+
+	for (y = 0; y < h; y++) {
+		for (x = 0; x < w; x++) {
+			float fy = float(y) / float(h) + offy;
+			float fx = float(x) / float(w) + offx;
+
+	fx *= scale;
+	fy *= scale;
+	
+			float sn =
+	snoise(fx, fy) * 1.0
+	+ snoise(fx*2.0,fy*6.0) * 0.25
+	+ snoise(fx*24.0,fy*4.0) * 0.125 // 0.0625
+#if 0 
+	+ snoise(fx*8.0,fy*16.0) * 0.0625 // 0.015625
+#endif
+	;
+
+#if 1
+	if (sn < -1.0) sn = -1.0;
+	if (sn > 1.0) sn = 1.0;
+#endif
+
+			data[y*w+x] = 127.0 * (sn + 1.0);
+#if 0
+			if ((sn + (1.0-fy) * 1.0 ) > 0.75)
+				data[y*w+x] = 0xff;
+			else
+				data[y*w+x] = 0x00;
+#endif
+		}
+	}
+
+	glClear(GL_COLOR_BUFFER_BIT);
+
+	pgm.use();
+
+	glActiveTexture(GL_TEXTURE0);
+	glBindTexture(GL_TEXTURE_2D, tex0);
+	glTexImage2D(GL_TEXTURE_2D, 0, GL_ALPHA, w, h, 0, GL_ALPHA, GL_UNSIGNED_BYTE, data);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+
+	glUniform1i(uTexture, 0);
+
+	glBindBuffer(GL_ARRAY_BUFFER, 0);
+	glVertexAttribPointer(aVertex, 2, GL_FLOAT, GL_FALSE, 4*4, vtx_xy_uv);
+	glVertexAttribPointer(aTexCoord, 2, GL_FLOAT, GL_FALSE, 4*4, vtx_xy_uv + 2);
+
+	glEnableVertexAttribArray(aVertex);
+	glEnableVertexAttribArray(aTexCoord);
+	glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
+	glDisableVertexAttribArray(aVertex);
+	glDisableVertexAttribArray(aTexCoord);
+
+	dtxt.clear();
+	//dtxt.printf("NoiseToy v0");
+	dtxt.printf("%f %f %f\n", offx, offy, scale);
+	dtxt.render();
+	return 0;
+}
+
+int main(int argc, char **argv) {
+	NoiseApp app;
+	app.setSize(512, 512);
+	app.setOptions(argc, argv);
+	return app.run();
+}