#include <stdio.h> #include <string.h> #include <stdlib.h> #ifndef WIN32 #include <unistd.h> #include <signal.h> #endif #include <GL/glew.h> #include <GL/glut.h> #include "readtex.c" #define TEXTURE_FILE "../images/bw.rgb" unsigned show_fps = 0; unsigned int frame_cnt = 0; void alarmhandler(int); static const char *filename = NULL; static GLuint fragShader; static GLuint vertShader; static GLuint program; static void usage(char *name) { fprintf(stderr, "usage: %s [ options ] shader_filename\n", name); #ifndef WIN32 fprintf(stderr, "\n" ); fprintf(stderr, "options:\n"); fprintf(stderr, " -fps show frames per second\n"); #endif } #ifndef WIN32 void alarmhandler (int sig) { if (sig == SIGALRM) { printf("%d frames in 5.0 seconds = %.3f FPS\n", frame_cnt, frame_cnt / 5.0); frame_cnt = 0; } signal(SIGALRM, alarmhandler); alarm(5); } #endif static void load_and_compile_shader(GLuint shader, const char *text) { GLint stat; glShaderSource(shader, 1, (const GLchar **) &text, NULL); glCompileShader(shader); glGetShaderiv(shader, GL_COMPILE_STATUS, &stat); if (!stat) { GLchar log[1000]; GLsizei len; glGetShaderInfoLog(shader, 1000, &len, log); fprintf(stderr, "fp-tri: problem compiling shader:\n%s\n", log); exit(1); } } static void read_shader(GLuint shader, const char *filename) { const int max = 100*1000; int n; char *buffer = (char*) malloc(max); FILE *f = fopen(filename, "r"); if (!f) { fprintf(stderr, "fp-tri: Unable to open shader file %s\n", filename); exit(1); } n = fread(buffer, 1, max, f); printf("fp-tri: read %d bytes from shader file %s\n", n, filename); if (n > 0) { buffer[n] = 0; load_and_compile_shader(shader, buffer); } fclose(f); free(buffer); } static void check_link(GLuint prog) { GLint stat; glGetProgramiv(prog, GL_LINK_STATUS, &stat); if (!stat) { GLchar log[1000]; GLsizei len; glGetProgramInfoLog(prog, 1000, &len, log); fprintf(stderr, "Linker error:\n%s\n", log); } } static void setup_uniforms() { { GLint loc1f = glGetUniformLocationARB(program, "Offset1f"); GLint loc2f = glGetUniformLocationARB(program, "Offset2f"); GLint loc4f = glGetUniformLocationARB(program, "Offset4f"); GLfloat vecKer[] = { 1.0, 0.0, 0.0, 1.0, 0.0, 1.0, 0.0, 1.0, 1.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0 }; if (loc1f >= 0) glUniform1fv(loc1f, 16, vecKer); if (loc2f >= 0) glUniform2fv(loc2f, 8, vecKer); if (loc4f >= 0) glUniform4fv(loc4f, 4, vecKer); } { GLint loci = glGetUniformLocationARB(program, "KernelSizeInt"); if (loci >= 0) glUniform1i(loci, 4); } { GLint loc1f = glGetUniformLocationARB(program, "KernelValue1f"); GLint loc2f = glGetUniformLocationARB(program, "KernelValue2f"); GLint loc4f = glGetUniformLocationARB(program, "KernelValue4f"); GLfloat vecKer[] = { 1.0, 0.0, 0.0, 0.25, 0.0, 1.0, 0.0, 0.25, 0.0, 0.0, 1.0, 0.25, 0.0, 0.0, 0.0, 0.25, 0.5, 0.0, 0.0, 0.35, 0.0, 0.5, 0.0, 0.35, 0.0, 0.0, 0.5, 0.35, 0.0, 0.0, 0.0, 0.35 }; if (loc1f >= 0) glUniform1fv(loc1f, 16, vecKer); if (loc2f >= 0) glUniform2fv(loc2f, 8, vecKer); if (loc4f >= 0) glUniform4fv(loc4f, 4, vecKer); } } static void prepare_shaders() { static const char *fragShaderText = "void main() {\n" " gl_FragColor = gl_Color;\n" "}\n"; static const char *vertShaderText = "void main() {\n" " gl_FrontColor = gl_Color;\n" " gl_Position = gl_ModelViewProjectionMatrix * gl_Vertex;\n" "}\n"; fragShader = glCreateShader(GL_FRAGMENT_SHADER); if (filename) read_shader(fragShader, filename); else load_and_compile_shader(fragShader, fragShaderText); vertShader = glCreateShader(GL_VERTEX_SHADER); load_and_compile_shader(vertShader, vertShaderText); program = glCreateProgram(); glAttachShader(program, fragShader); glAttachShader(program, vertShader); glLinkProgram(program); check_link(program); glUseProgram(program); setup_uniforms(); } #define LEVELS 8 #define SIZE (1<<LEVELS) static int TexWidth = SIZE, TexHeight = SIZE; static void ResetTextureLevel( int i ) { GLubyte tex2d[SIZE*SIZE][4]; { GLint Width = TexWidth / (1 << i); GLint Height = TexHeight / (1 << i); GLint s, t; for (s = 0; s < Width; s++) { for (t = 0; t < Height; t++) { tex2d[t*Width+s][0] = ((s / 16) % 2) ? 0 : 255; tex2d[t*Width+s][1] = ((t / 16) % 2) ? 0 : 255; tex2d[t*Width+s][2] = 128; tex2d[t*Width+s][3] = 255; } } glPixelStorei(GL_UNPACK_ALIGNMENT, 1); glTexImage2D(GL_TEXTURE_2D, i, GL_RGB, Width, Height, 0, GL_RGBA, GL_UNSIGNED_BYTE, tex2d); } } static void ResetTexture( void ) { int i; for (i = 0; i <= LEVELS; i++) { ResetTextureLevel(i); } } static void Init( void ) { GLuint Texture; /* Load texture */ glGenTextures(1, &Texture); glBindTexture(GL_TEXTURE_2D, Texture); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR); glPixelStorei(GL_UNPACK_ALIGNMENT, 1); if (!LoadRGBMipmaps(TEXTURE_FILE, GL_RGB)) { printf("Error: couldn't load texture image file %s\n", TEXTURE_FILE); exit(1); } glGenTextures(1, &Texture); glActiveTextureARB(GL_TEXTURE0_ARB + 1); glBindTexture(GL_TEXTURE_2D, Texture); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST); glPixelStorei(GL_UNPACK_ALIGNMENT, 1); { GLubyte data[32][32]; int width = 32; int height = 32; int i; int j; for (i = 0; i < 32; i++) for (j = 0; j < 32; j++) { /** ** +-----------+ ** | W | ** | +-----+ | ** | | | | ** | | B | | ** | | | | ** | +-----+ | ** | | ** +-----------+ **/ int i2 = i - height / 2; int j2 = j - width / 2; int h8 = height / 8; int w8 = width / 8; if ( -h8 <= i2 && i2 <= h8 && -w8 <= j2 && j2 <= w8 ) { data[i][j] = 0x00; } else if ( -2 * h8 <= i2 && i2 <= 2 * h8 && -2 * w8 <= j2 && j2 <= 2 * w8 ) { data[i][j] = 0x55; } else if ( -3 * h8 <= i2 && i2 <= 3 * h8 && -3 * w8 <= j2 && j2 <= 3 * w8 ) { data[i][j] = 0xaa; } else { data[i][j] = 0xff; } } glTexImage2D( GL_TEXTURE_2D, 0, GL_ALPHA8, 32, 32, 0, GL_ALPHA, GL_UNSIGNED_BYTE, data ); } glGenTextures(1, &Texture); glActiveTextureARB(GL_TEXTURE0_ARB + 2); glBindTexture(GL_TEXTURE_2D, Texture); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST_MIPMAP_NEAREST); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST); glPixelStorei(GL_UNPACK_ALIGNMENT, 1); ResetTexture(); glClearColor(.1, .3, .5, 0); } static void args(int argc, char *argv[]) { GLint i; for (i = 1; i < argc; i++) { if (strcmp(argv[i], "-fps") == 0) { show_fps = 1; } else if (i == argc - 1) { filename = argv[i]; } else { usage(argv[0]); exit(1); } } } static void Reshape(int width, int height) { glViewport(0, 0, (GLint)width, (GLint)height); glMatrixMode(GL_PROJECTION); glLoadIdentity(); glOrtho(-1.0, 1.0, -1.0, 1.0, -0.5, 1000.0); glMatrixMode(GL_MODELVIEW); } static void CleanUp(void) { glDeleteShader(fragShader); glDeleteShader(vertShader); glDeleteProgram(program); } static void Key(unsigned char key, int x, int y) { switch (key) { case 27: CleanUp(); exit(1); default: break; } glutPostRedisplay(); } static void Display(void) { glClear(GL_COLOR_BUFFER_BIT); glUseProgram(program); glProgramLocalParameter4fARB(GL_FRAGMENT_PROGRAM_ARB, 0, 1.0, 1.0, 0.0, 0.0); glProgramLocalParameter4fARB(GL_FRAGMENT_PROGRAM_ARB, 1, 0.0, 0.0, 1.0, 1.0); glBegin(GL_TRIANGLES); glColor3f(0,0,1); glTexCoord3f(1,1,0); glVertex3f( 0.9, -0.9, -30.0); glColor3f(1,0,0); glTexCoord3f(1,-1,0); glVertex3f( 0.9, 0.9, -30.0); glColor3f(0,1,0); glTexCoord3f(-1,0,0); glVertex3f(-0.9, 0.0, -30.0); glEnd(); glFlush(); if (show_fps) { ++frame_cnt; glutPostRedisplay(); } } int main(int argc, char **argv) { glutInit(&argc, argv); glutInitWindowPosition(0, 0); glutInitWindowSize(250, 250); glutInitDisplayMode(GLUT_RGB | GLUT_SINGLE | GLUT_DEPTH); args(argc, argv); glutCreateWindow(filename ? filename : "fp-tri"); glewInit(); glutReshapeFunc(Reshape); glutKeyboardFunc(Key); glutDisplayFunc(Display); prepare_shaders(); Init(); #ifndef WIN32 if (show_fps) { signal(SIGALRM, alarmhandler); alarm(5); } #endif glutMainLoop(); return 0; }