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Diffstat (limited to 'progs/glsl/convolutions.c')
-rw-r--r--progs/glsl/convolutions.c441
1 files changed, 441 insertions, 0 deletions
diff --git a/progs/glsl/convolutions.c b/progs/glsl/convolutions.c
new file mode 100644
index 0000000000..be887714c4
--- /dev/null
+++ b/progs/glsl/convolutions.c
@@ -0,0 +1,441 @@
+#define GL_GLEXT_PROTOTYPES
+#include "readtex.h"
+
+#include <GL/glut.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <assert.h>
+#include <math.h>
+
+enum Filter {
+ GAUSSIAN_BLUR,
+ SHARPEN,
+ MEAN_REMOVAL,
+ EMBOSS,
+ NO_FILTER,
+ LAST
+};
+#define QUIT LAST
+
+struct BoundingBox {
+ float minx, miny, minz;
+ float maxx, maxy, maxz;
+};
+struct Texture {
+ GLuint id;
+ GLfloat x;
+ GLfloat y;
+ GLint width;
+ GLint height;
+ GLenum format;
+};
+
+static const char *textureLocation = "../images/girl2.rgb";
+
+static GLfloat viewRotx = 0.0, viewRoty = 0.0, viewRotz = 0.0;
+static struct BoundingBox box;
+static struct Texture texture;
+static GLuint program;
+static GLint menuId;
+static enum Filter filter = GAUSSIAN_BLUR;
+
+
+static void checkError(int line)
+{
+ GLenum err = glGetError();
+ if (err) {
+ printf("GL Error %s (0x%x) at line %d\n",
+ gluErrorString(err), (int) err, line);
+ }
+}
+
+static void loadAndCompileShader(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, "Problem compiling shader: %s\n", log);
+ exit(1);
+ }
+ else {
+ printf("Shader compiled OK\n");
+ }
+}
+
+static void readShader(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, "Unable to open shader file %s\n", filename);
+ exit(1);
+ }
+
+ n = fread(buffer, 1, max, f);
+ printf("Read %d bytes from shader file %s\n", n, filename);
+ if (n > 0) {
+ buffer[n] = 0;
+ loadAndCompileShader(shader, buffer);
+ }
+
+ fclose(f);
+ free(buffer);
+}
+
+
+static void
+checkLink(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);
+ }
+ else {
+ fprintf(stderr, "Link success!\n");
+ }
+}
+
+static void fillConvolution(GLint *k,
+ GLfloat *scale,
+ GLfloat *color)
+{
+ switch(filter) {
+ case GAUSSIAN_BLUR:
+ k[0] = 1; k[1] = 2; k[2] = 1;
+ k[3] = 2; k[4] = 4; k[5] = 2;
+ k[6] = 1; k[7] = 2; k[8] = 1;
+
+ *scale = 1./16.;
+ break;
+ case SHARPEN:
+ k[0] = 0; k[1] = -2; k[2] = 0;
+ k[3] = -2; k[4] = 11; k[5] = -2;
+ k[6] = 0; k[7] = -2; k[8] = 0;
+
+ *scale = 1./3.;
+ break;
+ case MEAN_REMOVAL:
+ k[0] = -1; k[1] = -1; k[2] = -1;
+ k[3] = -1; k[4] = 9; k[5] = -1;
+ k[6] = -1; k[7] = -1; k[8] = -1;
+
+ *scale = 1./1.;
+ break;
+ case EMBOSS:
+ k[0] = -1; k[1] = 0; k[2] = -1;
+ k[3] = 0; k[4] = 4; k[5] = 0;
+ k[6] = -1; k[7] = 0; k[8] = -1;
+
+ *scale = 1./1.;
+ color[0] = 0.5;
+ color[1] = 0.5;
+ color[2] = 0.5;
+ color[3] = 0.5;
+ break;
+ case NO_FILTER:
+ k[0] = 0; k[1] = 0; k[2] = 0;
+ k[3] = 0; k[4] = 1; k[5] = 0;
+ k[6] = 0; k[7] = 0; k[8] = 0;
+
+ *scale = 1.;
+ break;
+ default:
+ assert(!"Unhandled switch value");
+ }
+}
+
+static void setupConvolution()
+{
+ GLint *kernel = (GLint*)malloc(sizeof(GLint) * 9);
+ GLfloat scale;
+ GLfloat *vecKer = (GLfloat*)malloc(sizeof(GLfloat) * 9 * 4);
+ GLuint loc;
+ GLuint i;
+ GLfloat baseColor[4];
+ baseColor[0] = 0;
+ baseColor[1] = 0;
+ baseColor[2] = 0;
+ baseColor[3] = 0;
+
+ fillConvolution(kernel, &scale, baseColor);
+ /*vector of 4*/
+ for (i = 0; i < 9; ++i) {
+ vecKer[i*4 + 0] = kernel[i];
+ vecKer[i*4 + 1] = kernel[i];
+ vecKer[i*4 + 2] = kernel[i];
+ vecKer[i*4 + 3] = kernel[i];
+ }
+
+ loc = glGetUniformLocationARB(program, "KernelValue");
+ glUniform4fv(loc, 9, vecKer);
+ loc = glGetUniformLocationARB(program, "ScaleFactor");
+ glUniform4f(loc, scale, scale, scale, scale);
+ loc = glGetUniformLocationARB(program, "BaseColor");
+ glUniform4f(loc, baseColor[0], baseColor[1],
+ baseColor[2], baseColor[3]);
+
+ free(vecKer);
+ free(kernel);
+}
+
+static void createProgram(const char *vertProgFile,
+ const char *fragProgFile)
+{
+ GLuint fragShader = 0, vertShader = 0;
+
+ program = glCreateProgram();
+ if (vertProgFile) {
+ vertShader = glCreateShader(GL_VERTEX_SHADER);
+ readShader(vertShader, vertProgFile);
+ glAttachShader(program, vertShader);
+ }
+
+ if (fragProgFile) {
+ fragShader = glCreateShader(GL_FRAGMENT_SHADER);
+ readShader(fragShader, fragProgFile);
+ glAttachShader(program, fragShader);
+ }
+
+ glLinkProgram(program);
+ checkLink(program);
+
+ glUseProgram(program);
+
+ assert(glIsProgram(program));
+ assert(glIsShader(fragShader));
+ assert(glIsShader(vertShader));
+
+ checkError(__LINE__);
+ {/*texture*/
+ GLuint texLoc = glGetUniformLocationARB(program, "srcTex");
+ glUniform1iARB(texLoc, 0);
+ }
+ {/*setup offsets */
+ float offsets[] = { 1.0 / texture.width, 1.0 / texture.height,
+ 0.0 , 1.0 / texture.height,
+ -1.0 / texture.width, 1.0 / texture.height,
+ 1.0 / texture.width, 0.0,
+ 0.0 , 0.0,
+ -1.0 / texture.width, 0.0,
+ 1.0 / texture.width, -1.0 / texture.height,
+ 0.0 , -1.0 / texture.height,
+ -1.0 / texture.width, -1.0 / texture.height };
+ GLuint offsetLoc = glGetUniformLocationARB(program, "Offset");
+ glUniform2fv(offsetLoc, 9, offsets);
+ }
+ setupConvolution();
+
+ checkError(__LINE__);
+}
+
+
+static void readTexture(const char *filename)
+{
+ GLubyte *data;
+
+ texture.x = 0;
+ texture.y = 0;
+
+ glGenTextures(1, &texture.id);
+ glBindTexture(GL_TEXTURE_2D, texture.id);
+ glTexParameteri(GL_TEXTURE_2D,
+ GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+ glTexParameteri(GL_TEXTURE_2D,
+ GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+ glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);
+ glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);
+ glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);
+ data = LoadRGBImage(filename, &texture.width, &texture.height,
+ &texture.format);
+ if (!data) {
+ printf("Error: couldn't load texture image '%s'\n", filename);
+ exit(1);
+ }
+ printf("Texture %s (%d x %d)\n",
+ filename, texture.width, texture.height);
+ glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB,
+ texture.width, texture.height, 0, texture.format,
+ GL_UNSIGNED_BYTE, data);
+}
+
+static void menuSelected(int entry)
+{
+ switch (entry) {
+ case QUIT:
+ exit(0);
+ break;
+ default:
+ filter = (enum Filter)entry;
+ }
+ setupConvolution();
+
+ glutPostRedisplay();
+}
+
+static void menuInit()
+{
+ menuId = glutCreateMenu(menuSelected);
+
+ glutAddMenuEntry("Gaussian blur", GAUSSIAN_BLUR);
+ glutAddMenuEntry("Sharpen", SHARPEN);
+ glutAddMenuEntry("Mean removal", MEAN_REMOVAL);
+ glutAddMenuEntry("Emboss", EMBOSS);
+ glutAddMenuEntry("None", NO_FILTER);
+
+ glutAddMenuEntry("Quit", QUIT);
+
+ glutAttachMenu(GLUT_RIGHT_BUTTON);
+}
+
+static void init()
+{
+ fprintf(stderr, "GL_RENDERER = %s\n", (char *) glGetString(GL_RENDERER));
+ fprintf(stderr, "GL_VERSION = %s\n", (char *) glGetString(GL_VERSION));
+ fprintf(stderr, "GL_VENDOR = %s\n", (char *) glGetString(GL_VENDOR));
+
+ menuInit();
+ readTexture(textureLocation);
+ createProgram("convolution.vert", "convolution.frag");
+
+ glEnable(GL_TEXTURE_2D);
+ glClearColor(1.0, 1.0, 1.0, 1.0);
+ /*glShadeModel(GL_SMOOTH);*/
+ glShadeModel(GL_FLAT);
+}
+
+static void reshape(int width, int height)
+{
+ glViewport(0, 0, width, height);
+ glMatrixMode(GL_PROJECTION);
+ glLoadIdentity();
+ box.minx = 0;
+ box.maxx = width;
+ box.miny = 0;
+ box.maxy = height;
+ box.minz = 0;
+ box.maxz = 1;
+ glOrtho(box.minx, box.maxx, box.miny, box.maxy, -999999, 999999);
+ glMatrixMode(GL_MODELVIEW);
+}
+
+static void keyPress(unsigned char key, int x, int y)
+{
+ switch(key) {
+ case 27:
+ exit(0);
+ default:
+ return;
+ }
+ glutPostRedisplay();
+}
+
+static void
+special(int k, int x, int y)
+{
+ switch (k) {
+ case GLUT_KEY_UP:
+ viewRotx += 2.0;
+ break;
+ case GLUT_KEY_DOWN:
+ viewRotx -= 2.0;
+ break;
+ case GLUT_KEY_LEFT:
+ viewRoty += 2.0;
+ break;
+ case GLUT_KEY_RIGHT:
+ viewRoty -= 2.0;
+ break;
+ default:
+ return;
+ }
+ glutPostRedisplay();
+}
+
+
+static void draw()
+{
+ GLfloat center[2];
+ GLfloat anchor[2];
+
+ glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+
+ glLoadIdentity();
+ glPushMatrix();
+
+ center[0] = box.maxx/2;
+ center[1] = box.maxy/2;
+ anchor[0] = center[0] - texture.width/2;
+ anchor[1] = center[1] - texture.height/2;
+
+ glTranslatef(center[0], center[1], 0);
+ glRotatef(viewRotx, 1.0, 0.0, 0.0);
+ glRotatef(viewRoty, 0.0, 1.0, 0.0);
+ glRotatef(viewRotz, 0.0, 0.0, 1.0);
+ glTranslatef(-center[0], -center[1], 0);
+
+ glTranslatef(anchor[0], anchor[1], 0);
+ glBegin(GL_TRIANGLE_STRIP);
+ {
+ glColor3f(1., 0., 0.);
+ glTexCoord2f(0, 0);
+ glVertex3f(0, 0, 0);
+
+ glColor3f(0., 1., 0.);
+ glTexCoord2f(0, 1.0);
+ glVertex3f(0, texture.height, 0);
+
+ glColor3f(1., 0., 0.);
+ glTexCoord2f(1.0, 0);
+ glVertex3f(texture.width, 0, 0);
+
+ glColor3f(0., 1., 0.);
+ glTexCoord2f(1, 1);
+ glVertex3f(texture.width, texture.height, 0);
+ }
+ glEnd();
+
+ glPopMatrix();
+
+ glFlush();
+
+ glutSwapBuffers();
+}
+
+int main(int argc, char **argv)
+{
+ glutInit(&argc, argv);
+
+ glutInitWindowPosition(0, 0);
+ glutInitWindowSize(400, 400);
+ glutInitDisplayMode(GLUT_RGB | GLUT_ALPHA | GLUT_DOUBLE);
+
+ if (!glutCreateWindow("Image Convolutions")) {
+ fprintf(stderr, "Couldn't create window!\n");
+ exit(1);
+ }
+
+ init();
+
+ glutReshapeFunc(reshape);
+ glutKeyboardFunc(keyPress);
+ glutSpecialFunc(special);
+ glutDisplayFunc(draw);
+
+
+ glutMainLoop();
+ return 0;
+}
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