diff options
Diffstat (limited to 'progs/glsl')
| -rw-r--r-- | progs/glsl/Makefile | 9 | ||||
| -rw-r--r-- | progs/glsl/vert-tex.c | 279 |
2 files changed, 287 insertions, 1 deletions
diff --git a/progs/glsl/Makefile b/progs/glsl/Makefile index 7c3e750882..ab024cecad 100644 --- a/progs/glsl/Makefile +++ b/progs/glsl/Makefile @@ -25,7 +25,8 @@ PROGS = \ texdemo1 \ toyball \ twoside \ - trirast + trirast \ + vert-tex ##### RULES ##### @@ -184,6 +185,12 @@ trirast: trirast.o shaderutil.o $(CC) -I$(INCDIR) $(CFLAGS) $(LDFLAGS) trirast.o shaderutil.o $(LIBS) -o $@ +vert-tex.o: vert-tex.c extfuncs.h shaderutil.h + $(CC) -c -I$(INCDIR) $(CFLAGS) vert-tex.c + +vert-tex: vert-tex.o shaderutil.o + $(CC) -I$(INCDIR) $(CFLAGS) $(LDFLAGS) vert-tex.o shaderutil.o $(LIBS) -o $@ + diff --git a/progs/glsl/vert-tex.c b/progs/glsl/vert-tex.c new file mode 100644 index 0000000000..9d00a61054 --- /dev/null +++ b/progs/glsl/vert-tex.c @@ -0,0 +1,279 @@ +/** + * 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/gl.h> +#include <GL/glut.h> +#include <GL/glext.h> +#include "extfuncs.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; + + +/* value[0] = tex unit */ +static struct uniform_info Uniforms[] = { + { "tex1", 1, GL_INT, { 0, 0, 0, 0 }, -1 }, + END_OF_UNIFORMS +}; + + + +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_func(fragShader); + glDeleteShader_func(vertShader); + glDeleteProgram_func(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); + + GetExtensionFuncs(); + + vertShader = CompileShaderText(GL_VERTEX_SHADER, VertShaderText); + fragShader = CompileShaderText(GL_FRAGMENT_SHADER, FragShaderText); + program = LinkShaders(vertShader, fragShader); + + glUseProgram_func(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]); + glutReshapeFunc(Reshape); + glutKeyboardFunc(Key); + glutSpecialFunc(SpecialKey); + glutDisplayFunc(Redisplay); + Init(); + if (Anim) + glutIdleFunc(Idle); + glutMainLoop(); + return 0; +} + |