diff options
| -rw-r--r-- | progs/glsl/Makefile | 9 | ||||
| -rw-r--r-- | progs/glsl/vert-or-frag-only.c | 191 |
2 files changed, 200 insertions, 0 deletions
diff --git a/progs/glsl/Makefile b/progs/glsl/Makefile index 71ca0af941..d21dcb6560 100644 --- a/progs/glsl/Makefile +++ b/progs/glsl/Makefile @@ -28,6 +28,7 @@ PROGS = \ toyball \ twoside \ trirast \ + vert-or-frag-only \ vert-tex @@ -193,6 +194,14 @@ trirast: trirast.o shaderutil.o $(CC) -I$(INCDIR) $(CFLAGS) $(LDFLAGS) trirast.o shaderutil.o $(LIBS) -o $@ +vert-or-frag-only.o: vert-or-frag-only.c extfuncs.h shaderutil.h + $(CC) -c -I$(INCDIR) $(CFLAGS) vert-or-frag-only.c + +vert-or-frag-only: vert-or-frag-only.o shaderutil.o + $(CC) -I$(INCDIR) $(CFLAGS) $(LDFLAGS) vert-or-frag-only.o shaderutil.o $(LIBS) -o $@ + + + vert-tex.o: vert-tex.c extfuncs.h shaderutil.h $(CC) -c -I$(INCDIR) $(CFLAGS) vert-tex.c diff --git a/progs/glsl/vert-or-frag-only.c b/progs/glsl/vert-or-frag-only.c new file mode 100644 index 0000000000..f6eedd8327 --- /dev/null +++ b/progs/glsl/vert-or-frag-only.c @@ -0,0 +1,191 @@ +/** + * Draw two quads, one using only a vertex shader, the other only with a + * fragment shader. They should appear the same. + * 17 Dec 2008 + * Brian Paul + */ + + +#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 char *FragProgFile = NULL; +static char *VertProgFile = NULL; +static GLuint FragShader; +static GLuint VertShader; +static GLuint VertProgram; /* w/out vertex shader */ +static GLuint FragProgram; /* w/out fragment shader */ +static GLint Win = 0; + + +static void +DrawQuadColor(void) +{ + glBegin(GL_QUADS); + glColor3f(1, 0, 0); glVertex2f(-1, -1); + glColor3f(0, 1, 0); glVertex2f( 1, -1); + glColor3f(0, 0, 1); glVertex2f( 1, 1); + glColor3f(1, 0, 1); glVertex2f(-1, 1); + glEnd(); +} + + +/** as above, but specify color via texcoords */ +static void +DrawQuadTex(void) +{ + glBegin(GL_QUADS); + glTexCoord3f(1, 0, 0); glVertex2f(-1, -1); + glTexCoord3f(0, 1, 0); glVertex2f( 1, -1); + glTexCoord3f(0, 0, 1); glVertex2f( 1, 1); + glTexCoord3f(1, 0, 1); glVertex2f(-1, 1); + glEnd(); +} + + +static void +Redisplay(void) +{ + glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); + + /* render with vertex shader only */ + glUseProgram_func(VertProgram); + glPushMatrix(); + glTranslatef(-1.5, 0, 0); + DrawQuadTex(); + glPopMatrix(); + + /* render with fragment shader only */ + glUseProgram_func(FragProgram); + glPushMatrix(); + glTranslatef(+1.5, 0, 0); + DrawQuadColor(); + glPopMatrix(); + + glutSwapBuffers(); +} + + +static void +Reshape(int width, int height) +{ + glViewport(0, 0, width, height); + glMatrixMode(GL_PROJECTION); + glLoadIdentity(); + glOrtho(-4, 4, -2, 2, -1, 1); + glMatrixMode(GL_MODELVIEW); + glLoadIdentity(); +} + + +static void +CleanUp(void) +{ + glDeleteShader_func(FragShader); + glDeleteShader_func(VertShader); + glDeleteProgram_func(VertProgram); + glDeleteProgram_func(FragProgram); + glutDestroyWindow(Win); +} + + +static void +Key(unsigned char key, int x, int y) +{ + (void) x; + (void) y; + switch(key) { + case 27: + CleanUp(); + exit(0); + break; + } + glutPostRedisplay(); +} + + +static void +Init(void) +{ + static const char *fragShaderText = + "void main() {\n" + " gl_FragColor = gl_Color;\n" + "}\n"; + static const char *vertShaderText = + "void main() {\n" + " gl_Position = ftransform();\n" + " gl_FrontColor = gl_MultiTexCoord0;\n" /* see DrawQuadTex() */ + "}\n"; + + if (!ShadersSupported()) + exit(1); + + GetExtensionFuncs(); + + if (FragProgFile) + FragShader = CompileShaderFile(GL_FRAGMENT_SHADER, FragProgFile); + else + FragShader = CompileShaderText(GL_FRAGMENT_SHADER, fragShaderText); + + if (VertProgFile) + VertShader = CompileShaderFile(GL_VERTEX_SHADER, VertProgFile); + else + VertShader = CompileShaderText(GL_VERTEX_SHADER, vertShaderText); + + VertProgram = LinkShaders(VertShader, 0); + FragProgram = LinkShaders(0, FragShader); + + glClearColor(0.3f, 0.3f, 0.3f, 0.0f); + glEnable(GL_DEPTH_TEST); + + printf("GL_RENDERER = %s\n",(const char *) glGetString(GL_RENDERER)); + + assert(glIsProgram_func(VertProgram)); + assert(glIsProgram_func(FragProgram)); + assert(glIsShader_func(FragShader)); + assert(glIsShader_func(VertShader)); + + glColor3f(1, 0, 0); +} + + +static void +ParseOptions(int argc, char *argv[]) +{ + int i; + for (i = 1; i < argc; i++) { + if (strcmp(argv[i], "-fs") == 0) { + FragProgFile = argv[i+1]; + } + else if (strcmp(argv[i], "-vs") == 0) { + VertProgFile = argv[i+1]; + } + } +} + + +int +main(int argc, char *argv[]) +{ + glutInit(&argc, argv); + glutInitWindowPosition( 0, 0); + glutInitWindowSize(400, 200); + glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH); + Win = glutCreateWindow(argv[0]); + glutReshapeFunc(Reshape); + glutKeyboardFunc(Key); + glutDisplayFunc(Redisplay); + ParseOptions(argc, argv); + Init(); + glutMainLoop(); + return 0; +} |