glstuff

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

test4.cc (2611B)


      1 /* Copyright 2013 Brian Swetland <swetland@frotz.net>
      2  *
      3  * Licensed under the Apache License, Version 2.0 (the "License");
      4  * you may not use this file except in compliance with the License.
      5  * You may obtain a copy of the License at
      6  *
      7  *     http://www.apache.org/licenses/LICENSE-2.0
      8  *
      9  * Unless required by applicable law or agreed to in writing, software
     10  * distributed under the License is distributed on an "AS IS" BASIS,
     11  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     12  * See the License for the specific language governing permissions and
     13  * limitations under the License.
     14  */
     15 
     16 #include <stdio.h>
     17 #include <stdlib.h>
     18 #include <unistd.h>
     19 
     20 #include "app.h"
     21 #include "util.h"
     22 #include "matrix.h"
     23 #include "program.h"
     24 
     25 class TestApp : public App {
     26 public:
     27 	int init(void);
     28 	int render(void);
     29 private:
     30 	void *texdata;
     31 	unsigned texw, texh;
     32 
     33 	GLuint tex0;
     34 	GLuint aVertex, aTexCoord;
     35 	GLuint uMVP, uTexture;
     36 
     37 	Program pgm; 
     38 	mat4 MVP;
     39 };
     40 
     41 static GLfloat verts[] = {
     42 	-1, -1, 0,
     43 	-1, 1, 0,
     44 	1, -1, 0,
     45 	1, 1, 0,
     46 	-0.5f, -0.5f, 0.0f,
     47 	-0.5f, 0.5f, 0.0f,
     48 	0.5f, -0.5f, 0.0f,
     49 	0.5f, 0.5f, 0.0f,	
     50 };
     51 
     52 static GLfloat texcoords[] = {
     53 	0.0, 0.0,
     54 	0.0, 1.0,
     55 	1.0, 0.0,
     56 	1.0, 1.0,
     57 };
     58 
     59 int TestApp::init(void) {
     60 	if (!(texdata = load_png_gray("texture.sdf.png", &texw, &texh, 1)))
     61 		return -1;
     62 
     63 	if (pgm.compile("test4.vs","test4.fs"))
     64 		return -1;
     65 
     66 	aVertex = pgm.getAttribID("aVertex");
     67 	aTexCoord = pgm.getAttribID("aTexCoord");
     68 	uMVP = pgm.getUniformID("uMVP");
     69 	uTexture = pgm.getUniformID("uTexture");
     70 
     71 	MVP.setOrtho(-aspect(), aspect(), -1, 1, 1, -1);
     72 
     73 	glViewport(0, 0, width(), height());
     74 	glClearColor(0, 0, 0, 0);
     75 	glClearDepth(1.0f);
     76 
     77 	glEnable(GL_TEXTURE_2D);
     78 
     79 	glGenTextures(1, &tex0);
     80 	glBindTexture(GL_TEXTURE_2D, tex0);
     81 	glTexImage2D(GL_TEXTURE_2D, 0, GL_ALPHA, texw, texh, 0, GL_ALPHA,
     82 		GL_UNSIGNED_BYTE, texdata);
     83 	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
     84 	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
     85 
     86 	return 0;
     87 }
     88 
     89 int TestApp::render(void) {
     90 	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
     91 
     92 	pgm.use();
     93 
     94 	glActiveTexture(GL_TEXTURE0);
     95 	glBindTexture(GL_TEXTURE_2D, tex0);
     96 
     97 	glUniformMatrix4fv(uMVP, 1, GL_FALSE, MVP);
     98 	glUniform1i(uTexture, 0);
     99 
    100 	glVertexAttribPointer(aVertex, 3, GL_FLOAT, GL_FALSE, 0, verts);
    101 	glEnableVertexAttribArray(aVertex);
    102 
    103 	glVertexAttribPointer(aTexCoord, 2, GL_FLOAT, GL_FALSE, 0, texcoords);
    104 	glEnableVertexAttribArray(aTexCoord);
    105 
    106 	glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
    107 
    108 	return 0;
    109 }
    110 
    111 int main(int argc, char **argv) {
    112 	TestApp app;
    113 	app.setOptions(argc, argv);
    114 	return app.run();
    115 }
    116