+++ /dev/null
-/**
- * Implement glRasterPos + glBitmap with textures + shaders.
- * Brian Paul
- * 14 May 2007
- */
-
-#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 GLuint FragShader;
-static GLuint VertShader;
-static GLuint Program;
-
-static GLint Win = 0;
-static GLint WinWidth = 500, WinHeight = 500;
-static GLboolean Anim = GL_TRUE;
-static GLboolean Bitmap = GL_FALSE;
-static GLfloat Xrot = 20.0f, Yrot = 70.0f;
-static GLint uTex, uScale;
-static GLuint Textures[2];
-
-#define TEX_WIDTH 16
-#define TEX_HEIGHT 8
-
-
-static void
-BitmapText(const char *s)
-{
- while (*s) {
- glutBitmapCharacter(GLUT_BITMAP_8_BY_13, (int) *s);
- s++;
- }
-}
-
-
-static void
-Redisplay(void)
-{
- static const GLfloat px[3] = { 1.2, 0, 0};
- static const GLfloat nx[3] = {-1.2, 0, 0};
-
- 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);
-
- glEnable(GL_LIGHTING);
-
- glPushMatrix();
- glScalef(0.5, 0.5, 0.5);
- glutSolidDodecahedron();
- glPopMatrix();
-
- glDisable(GL_LIGHTING);
-
- glColor3f(0, 1, 0);
- glBegin(GL_LINES);
- glVertex3f(-1, 0, 0);
- glVertex3f( 1, 0, 0);
- glEnd();
-
- glColor3f(1, 1, 0);
-
- if (Bitmap) {
- glRasterPos3fv(px);
- BitmapText("+X");
- glRasterPos3fv(nx);
- BitmapText("-X");
- }
- else {
- glUseProgram(Program);
-
- /* vertex positions (deltas) depend on texture size and window size */
- if (uScale != -1) {
- glUniform2f(uScale,
- 2.0 * TEX_WIDTH / WinWidth,
- 2.0 * TEX_HEIGHT / WinHeight);
- }
-
- /* draw +X */
- glBindTexture(GL_TEXTURE_2D, Textures[0]);
- glBegin(GL_QUADS);
- glTexCoord2f(0, 0); glVertex3fv(px);
- glTexCoord2f(1, 0); glVertex3fv(px);
- glTexCoord2f(1, 1); glVertex3fv(px);
- glTexCoord2f(0, 1); glVertex3fv(px);
- glEnd();
-
- /* draw -X */
- glBindTexture(GL_TEXTURE_2D, Textures[1]);
- glBegin(GL_QUADS);
- glTexCoord2f(0, 0); glVertex3fv(nx);
- glTexCoord2f(1, 0); glVertex3fv(nx);
- glTexCoord2f(1, 1); glVertex3fv(nx);
- glTexCoord2f(0, 1); glVertex3fv(nx);
- glEnd();
-
- glUseProgram(0);
- }
-
- glPopMatrix();
-
- glutSwapBuffers();
-}
-
-
-static void
-Idle(void)
-{
- Yrot = glutGet(GLUT_ELAPSED_TIME) * 0.01;
- glutPostRedisplay();
-}
-
-
-static void
-Reshape(int width, int height)
-{
- WinWidth = width;
- WinHeight = 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, -10.0f);
-}
-
-
-static void
-Key(unsigned char key, int x, int y)
-{
- (void) x;
- (void) y;
-
- switch(key) {
- case ' ':
- case 'a':
- Anim = !Anim;
- if (Anim)
- glutIdleFunc(Idle);
- else
- glutIdleFunc(NULL);
- break;
- case 'b':
- Bitmap = !Bitmap;
- if (Bitmap)
- printf("Using glBitmap\n");
- else
- printf("Using billboard texture\n");
- break;
- case 27:
- glDeleteShader(FragShader);
- glDeleteShader(VertShader);
- glDeleteProgram(Program);
- glutDestroyWindow(Win);
- exit(0);
- }
- glutPostRedisplay();
-}
-
-
-static void
-SpecialKey(int key, int x, int y)
-{
- const GLfloat step = 0.125f;
- 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;
- }
- /*printf("Xrot: %f Yrot: %f\n", Xrot, Yrot);*/
- glutPostRedisplay();
-}
-
-
-static void
-MakeTexImage(const char *p, GLuint texobj)
-{
- GLubyte image[TEX_HEIGHT][TEX_WIDTH];
- GLuint i, j, k;
-
- for (i = 0; i < TEX_HEIGHT; i++) {
- for (j = 0; j < TEX_WIDTH; j++) {
- k = i * TEX_WIDTH + j;
- if (p[k] == ' ') {
- image[i][j] = 0;
- }
- else {
- image[i][j] = 255;
- }
- }
- }
-
- glBindTexture(GL_TEXTURE_2D, texobj);
- glTexImage2D(GL_TEXTURE_2D, 0, GL_INTENSITY, TEX_WIDTH, TEX_HEIGHT, 0,
- GL_RED, GL_UNSIGNED_BYTE, image);
- glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAX_LEVEL, 1);
- glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
- glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
-}
-
-
-static void
-MakeBitmapTextures(void)
-{
- const char *px =
- " X X "
- " X X X "
- " X X X "
- " XXXXX X "
- " X X X "
- " X X X "
- " X X "
- " X X ";
- const char *nx =
- " X X "
- " X X "
- " X X "
- " XXXXX X "
- " X X "
- " X X "
- " X X "
- " X X ";
- glGenTextures(2, Textures);
- MakeTexImage(px, Textures[0]);
- MakeTexImage(nx, Textures[1]);
-}
-
-
-static void
-Init(void)
-{
- /* Fragment shader: modulate raster color by texture, discard fragments
- * with alpha < 1.0
- */
- static const char *fragShaderText =
- "uniform sampler2D tex2d; \n"
- "void main() {\n"
- " vec4 c = texture2D(tex2d, gl_TexCoord[0].xy); \n"
- " if (c.w < 1.0) \n"
- " discard; \n"
- " gl_FragColor = c * gl_Color; \n"
- "}\n";
- /* Vertex shader: compute new vertex position based on incoming vertex pos,
- * texcoords and special scale factor.
- */
- static const char *vertShaderText =
- "uniform vec2 scale; \n"
- "void main() {\n"
- " vec4 p = gl_ModelViewProjectionMatrix * gl_Vertex;\n"
- " gl_Position.xy = p.xy + gl_MultiTexCoord0.xy * scale * p.w; \n"
- " gl_Position.zw = p.zw; \n"
- " gl_TexCoord[0] = gl_MultiTexCoord0; \n"
- " gl_FrontColor = gl_Color; \n"
- "}\n";
-
- if (!ShadersSupported())
- exit(1);
-
- VertShader = CompileShaderText(GL_VERTEX_SHADER, vertShaderText);
- FragShader = CompileShaderText(GL_FRAGMENT_SHADER, fragShaderText);
- Program = LinkShaders(VertShader, FragShader);
-
- glUseProgram(Program);
-
- uScale = glGetUniformLocation(Program, "scale");
- uTex = glGetUniformLocation(Program, "tex2d");
- if (uTex != -1) {
- glUniform1i(uTex, 0); /* tex unit 0 */
- }
-
- glUseProgram(0);
-
- glClearColor(0.3f, 0.3f, 0.3f, 0.0f);
- glEnable(GL_DEPTH_TEST);
- glEnable(GL_NORMALIZE);
- glEnable(GL_LIGHT0);
-
- MakeBitmapTextures();
-}
-
-
-int
-main(int argc, char *argv[])
-{
- glutInit(&argc, argv);
- glutInitWindowSize(WinWidth, WinHeight);
- glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);
- Win = glutCreateWindow(argv[0]);
- glewInit();
- glutReshapeFunc(Reshape);
- glutKeyboardFunc(Key);
- glutSpecialFunc(SpecialKey);
- glutDisplayFunc(Redisplay);
- if (Anim)
- glutIdleFunc(Idle);
- Init();
- glutMainLoop();
- return 0;
-}
-
-
projects / mesa.git / blobdiff