+++ /dev/null
-/**
- * Vertex shader texture sampling test.
- * Brian Paul
- * 2 Dec 2008
- */
-
-#include <assert.h>
-#include <string.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <math.h>
-#include <GL/glew.h>
-#include <GL/glut.h>
-#include "shaderutil.h"
-
-
-static const char *VertShaderText =
- "uniform sampler2D tex1; \n"
- "void main() \n"
- "{ \n"
- " vec4 pos = gl_Vertex; \n"
- " pos.z = texture2D(tex1, gl_MultiTexCoord0.xy).x - 0.5; \n"
- " gl_Position = gl_ModelViewProjectionMatrix * pos; \n"
- " gl_FrontColor = pos; \n"
- "} \n";
-
-static const char *FragShaderText =
- "void main() \n"
- "{ \n"
- " gl_FragColor = gl_Color; \n"
- "} \n";
-
-
-static GLuint fragShader;
-static GLuint vertShader;
-static GLuint program;
-
-static GLint win = 0;
-static GLboolean Anim = GL_TRUE;
-static GLboolean WireFrame = GL_TRUE;
-static GLfloat xRot = -70.0f, yRot = 0.0f, zRot = 0.0f;
-
-static void
-Idle(void)
-{
- zRot = 90 + glutGet(GLUT_ELAPSED_TIME) * 0.05;
- glutPostRedisplay();
-}
-
-
-static void
-DrawMesh(void)
-{
- GLfloat xmin = -2.0, xmax = 2.0;
- GLfloat ymin = -2.0, ymax = 2.0;
- GLuint xdivs = 20, ydivs = 20;
- GLfloat dx = (xmax - xmin) / xdivs;
- GLfloat dy = (ymax - ymin) / ydivs;
- GLfloat ds = 1.0 / xdivs, dt = 1.0 / ydivs;
- GLfloat x, y, s, t;
- GLuint i, j;
-
- y = ymin;
- t = 0.0;
- for (i = 0; i < ydivs; i++) {
- x = xmin;
- s = 0.0;
- glBegin(GL_QUAD_STRIP);
- for (j = 0; j < xdivs; j++) {
- glTexCoord2f(s, t);
- glVertex2f(x, y);
- glTexCoord2f(s, t + dt);
- glVertex2f(x, y + dy);
- x += dx;
- s += ds;
- }
- glEnd();
- y += dy;
- t += dt;
- }
-}
-
-
-static void
-Redisplay(void)
-{
- if (WireFrame)
- glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
- else
- glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
-
- glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
-
- glPushMatrix();
- glRotatef(xRot, 1.0f, 0.0f, 0.0f);
- glRotatef(yRot, 0.0f, 1.0f, 0.0f);
- glRotatef(zRot, 0.0f, 0.0f, 1.0f);
-
- glPushMatrix();
- DrawMesh();
- glPopMatrix();
-
- glPopMatrix();
-
- glutSwapBuffers();
-}
-
-
-static void
-Reshape(int width, int height)
-{
- glViewport(0, 0, width, height);
- glMatrixMode(GL_PROJECTION);
- glLoadIdentity();
- glFrustum(-1.0, 1.0, -1.0, 1.0, 5.0, 25.0);
- glMatrixMode(GL_MODELVIEW);
- glLoadIdentity();
- glTranslatef(0.0f, 0.0f, -15.0f);
-}
-
-
-static void
-CleanUp(void)
-{
- glDeleteShader(fragShader);
- glDeleteShader(vertShader);
- glDeleteProgram(program);
- glutDestroyWindow(win);
-}
-
-
-static void
-Key(unsigned char key, int x, int y)
-{
- const GLfloat step = 2.0;
- (void) x;
- (void) y;
-
- switch(key) {
- case 'a':
- Anim = !Anim;
- if (Anim)
- glutIdleFunc(Idle);
- else
- glutIdleFunc(NULL);
- break;
- case 'w':
- WireFrame = !WireFrame;
- break;
- case 'z':
- zRot += step;
- break;
- case 'Z':
- zRot -= step;
- break;
- case 27:
- CleanUp();
- exit(0);
- break;
- }
- glutPostRedisplay();
-}
-
-
-static void
-SpecialKey(int key, int x, int y)
-{
- const GLfloat step = 2.0;
-
- (void) x;
- (void) y;
-
- switch(key) {
- case GLUT_KEY_UP:
- xRot += step;
- break;
- case GLUT_KEY_DOWN:
- xRot -= step;
- break;
- case GLUT_KEY_LEFT:
- yRot -= step;
- break;
- case GLUT_KEY_RIGHT:
- yRot += step;
- break;
- }
- glutPostRedisplay();
-}
-
-
-static void
-MakeTexture(void)
-{
- const GLuint texWidth = 64, texHeight = 64;
- GLfloat texImage[64][64];
- GLuint i, j;
-
- /* texture is basically z = f(x, y) */
- for (i = 0; i < texHeight; i++) {
- GLfloat y = 2.0 * (i / (float) (texHeight - 1)) - 1.0;
- for (j = 0; j < texWidth; j++) {
- GLfloat x = 2.0 * (j / (float) (texWidth - 1)) - 1.0;
- GLfloat z = 0.5 + 0.5 * (sin(4.0 * x) * sin(4.0 * y));
- texImage[i][j] = z;
- }
- }
-
- glActiveTexture(GL_TEXTURE0);
- glBindTexture(GL_TEXTURE_2D, 42);
- glTexImage2D(GL_TEXTURE_2D, 0, GL_INTENSITY, texWidth, texHeight, 0,
- GL_LUMINANCE, GL_FLOAT, texImage);
- glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
- glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
-}
-
-
-static void
-Init(void)
-{
- GLint m;
-
- glGetIntegerv(GL_MAX_VERTEX_TEXTURE_IMAGE_UNITS_ARB, &m);
- if (m < 1) {
- printf("Error: no vertex shader texture units supported.\n");
- exit(1);
- }
-
- if (!ShadersSupported())
- exit(1);
-
- vertShader = CompileShaderText(GL_VERTEX_SHADER, VertShaderText);
- fragShader = CompileShaderText(GL_FRAGMENT_SHADER, FragShaderText);
- program = LinkShaders(vertShader, fragShader);
-
- glUseProgram(program);
-
- assert(glGetError() == 0);
-
- MakeTexture();
-
- glClearColor(0.4f, 0.4f, 0.8f, 0.0f);
-
- glEnable(GL_DEPTH_TEST);
-
- glColor3f(1, 1, 1);
-}
-
-
-int
-main(int argc, char *argv[])
-{
- glutInit(&argc, argv);
- glutInitWindowSize(500, 500);
- glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);
- win = glutCreateWindow(argv[0]);
- glewInit();
- glutReshapeFunc(Reshape);
- glutKeyboardFunc(Key);
- glutSpecialFunc(SpecialKey);
- glutDisplayFunc(Redisplay);
- Init();
- if (Anim)
- glutIdleFunc(Idle);
- glutMainLoop();
- return 0;
-}
-
projects / mesa.git / blobdiff