Demos (master): geom-wide-lines, geom-sprites - geometry shader demos
Brian Paul
brianp at kemper.freedesktop.org
Sat Mar 26 12:09:27 UTC 2011
Module: Demos
Branch: master
Commit: bc461a0a8f25dfeafbdbf2f3aca09fa085bacb5d
URL: http://cgit.freedesktop.org/mesa/demos/commit/?id=bc461a0a8f25dfeafbdbf2f3aca09fa085bacb5d
Author: Brian Paul <brianp at vmware.com>
Date: Sat Mar 26 06:06:04 2011 -0600
geom-wide-lines, geom-sprites - geometry shader demos
---
src/glsl/CMakeLists.txt | 2 +
src/glsl/Makefile.am | 4 +
src/glsl/geom-sprites.c | 330 ++++++++++++++++++++++++++++++++++++++++++++
src/glsl/geom-wide-lines.c | 309 +++++++++++++++++++++++++++++++++++++++++
4 files changed, 645 insertions(+), 0 deletions(-)
diff --git a/src/glsl/CMakeLists.txt b/src/glsl/CMakeLists.txt
index 63234ab..63b4801 100644
--- a/src/glsl/CMakeLists.txt
+++ b/src/glsl/CMakeLists.txt
@@ -28,6 +28,8 @@ set (targets
deriv
fragcoord
fsraytrace
+ geom-sprites
+ geom-wide-lines
identity
linktest
mandelbrot
diff --git a/src/glsl/Makefile.am b/src/glsl/Makefile.am
index 294a5f5..7f96a5c 100644
--- a/src/glsl/Makefile.am
+++ b/src/glsl/Makefile.am
@@ -41,6 +41,8 @@ bin_PROGRAMS = \
deriv \
fragcoord \
fsraytrace \
+ geom-sprites \
+ geom-wide-lines \
identity \
linktest \
mandelbrot \
@@ -76,6 +78,8 @@ brick_LDADD = ../util/libutil.la
bump_LDADD = ../util/libutil.la
convolutions_LDADD = ../util/libutil.la
deriv_LDADD = ../util/libutil.la
+geom_sprites_LDADD = ../util/libutil.la
+geom_wide_lines_LDADD = ../util/libutil.la
fsraytrace_LDADD = ../util/libutil.la
fragcoord_LDADD = ../util/libutil.la
identity_LDADD = ../util/libutil.la
diff --git a/src/glsl/geom-sprites.c b/src/glsl/geom-sprites.c
new file mode 100644
index 0000000..ce7ed4f
--- /dev/null
+++ b/src/glsl/geom-sprites.c
@@ -0,0 +1,330 @@
+/**
+ * Test using a geometry shader to implement point sprites.
+ * XXX we should also demo point size attenuation.
+ *
+ * Brian Paul
+ * March 2011
+ */
+
+#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"
+
+#ifndef M_PI
+#define M_PI 3.1415926535
+#endif
+
+static GLint WinWidth = 500, WinHeight = 500;
+static char *FragProgFile = NULL;
+static char *VertProgFile = NULL;
+static GLuint VertShader, GeomShader, FragShader;
+static GLuint Program;
+static GLint Win = 0;
+static GLboolean Anim = GL_TRUE;
+static GLfloat Xrot = 0, Yrot = 0;
+static int uPointSize = -1, uInverseViewportSize = -1;
+
+static const int NumPoints = 50;
+static float Points[100][3];
+
+static const GLfloat Red[4] = {1, 0, 0, 1};
+static const GLfloat Green[4] = {0, 1, 0, 0};
+
+
+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
+Redisplay(void)
+{
+ int i;
+
+ glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
+
+ glPushMatrix();
+ glRotatef(Xrot, 1, 0, 0);
+ glRotatef(Yrot, 0, 0, 1);
+
+ glBegin(GL_POINTS);
+ for (i = 0; i < NumPoints; i++) {
+ glVertex3fv(Points[i]);
+ }
+ glEnd();
+
+ glPopMatrix();
+
+ glutSwapBuffers();
+}
+
+
+static void
+Idle(void)
+{
+ int curTime = glutGet(GLUT_ELAPSED_TIME);
+ Xrot = curTime * 0.02;
+ Yrot = curTime * 0.05;
+ glutPostRedisplay();
+}
+
+
+static void
+Reshape(int width, int height)
+{
+ float ar = (float) width / height;
+ glViewport(0, 0, width, height);
+ glMatrixMode(GL_PROJECTION);
+ glLoadIdentity();
+ glFrustum(-ar, ar, -1, 1, 3, 25);
+ glMatrixMode(GL_MODELVIEW);
+ glLoadIdentity();
+ glTranslatef(0, 0, -10);
+
+ {
+ GLfloat viewport[4];
+ glGetFloatv(GL_VIEWPORT, viewport);
+ glUniform2f(uInverseViewportSize, 1.0F / viewport[2], 1.0F / viewport[3]);
+ }
+}
+
+
+static void
+CleanUp(void)
+{
+ glDeleteShader(FragShader);
+ glDeleteShader(VertShader);
+ glDeleteShader(GeomShader);
+ glDeleteProgram(Program);
+ glutDestroyWindow(Win);
+}
+
+
+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 27:
+ CleanUp();
+ exit(0);
+ break;
+ }
+ glutPostRedisplay();
+}
+
+
+static GLuint
+MakeTexture(void)
+{
+#define TEX_SIZE 32
+ GLubyte image[TEX_SIZE][TEX_SIZE][3];
+ GLuint i, j;
+ GLuint tex;
+
+ glGenTextures(1, &tex);
+ glBindTexture(GL_TEXTURE_2D, tex);
+
+ glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+ glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+
+ /* 'X' pattern */
+ for (i = 0; i < TEX_SIZE; i++) {
+ for (j = 0; j < TEX_SIZE; j++) {
+ int p1 = i - j, p2 = TEX_SIZE - 1 - i - j;
+ p1 = (p1 >= -2 && p1 <= 2);
+ p2 = (p2 >= -2 && p2 <= 2);
+ if (p1 || p2) {
+ image[i][j][0] = 255;
+ image[i][j][1] = 255;
+ image[i][j][2] = 255;
+ }
+ else {
+ image[i][j][0] = 50;
+ image[i][j][1] = 50;
+ image[i][j][2] = 50;
+ }
+ }
+ }
+
+ glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, TEX_SIZE, TEX_SIZE, 0,
+ GL_RGB, GL_UNSIGNED_BYTE, image);
+
+ return tex;
+}
+
+
+static void
+MakePoints(void)
+{
+ int i;
+ for (i = 0; i < NumPoints; i++) {
+ Points[i][0] = ((rand() % 2000) - 1000.0) / 500.0;
+ Points[i][1] = ((rand() % 2000) - 1000.0) / 500.0;
+ Points[i][2] = ((rand() % 2000) - 1000.0) / 500.0;
+ }
+}
+
+static void
+Init(void)
+{
+ static const char *fragShaderText =
+ "uniform sampler2D tex; \n"
+ "void main() \n"
+ "{ \n"
+ " gl_FragColor = texture2D(tex, gl_TexCoord[0].xy); \n"
+ "} \n";
+ static const char *vertShaderText =
+ "void main() \n"
+ "{ \n"
+ " gl_FrontColor = gl_Color; \n"
+ " gl_Position = ftransform(); \n"
+ "} \n";
+ static const char *geomShaderText =
+ "#version 120 \n"
+ "#extension GL_ARB_geometry_shader4: enable \n"
+ "uniform vec2 InverseViewportSize; \n"
+ "uniform float PointSize; \n"
+ "void main() \n"
+ "{ \n"
+ " vec4 pos = gl_PositionIn[0]; \n"
+ " vec2 d = vec2(PointSize * pos.w) * InverseViewportSize; \n"
+ " gl_FrontColor = gl_FrontColorIn[0]; \n"
+ " gl_TexCoord[0] = vec4(0, 0, 0, 1); \n"
+ " gl_Position = pos + vec4(-d.x, -d.y, 0, 0); \n"
+ " EmitVertex(); \n"
+ " gl_TexCoord[0] = vec4(1, 0, 0, 1); \n"
+ " gl_Position = pos + vec4( d.x, -d.y, 0, 0); \n"
+ " EmitVertex(); \n"
+ " gl_TexCoord[0] = vec4(0, 1, 0, 1); \n"
+ " gl_Position = pos + vec4(-d.x, d.y, 0, 0); \n"
+ " EmitVertex(); \n"
+ " gl_TexCoord[0] = vec4(1, 1, 0, 1); \n"
+ " gl_Position = pos + vec4( d.x, d.y, 0, 0); \n"
+ " EmitVertex(); \n"
+ "} \n";
+
+ if (!ShadersSupported())
+ exit(1);
+
+ if (!glutExtensionSupported("GL_ARB_geometry_shader4")) {
+ fprintf(stderr, "Sorry, GL_ARB_geometry_shader4 is not supported.\n");
+ exit(1);
+ }
+
+ VertShader = CompileShaderText(GL_VERTEX_SHADER, vertShaderText);
+ FragShader = CompileShaderText(GL_FRAGMENT_SHADER, fragShaderText);
+ GeomShader = CompileShaderText(GL_GEOMETRY_SHADER_ARB, geomShaderText);
+ assert(GeomShader);
+
+ Program = LinkShaders3(VertShader, GeomShader, FragShader);
+ assert(Program);
+ CheckError(__LINE__);
+
+ /*
+ * The geometry shader will convert incoming points to quads (4-vertex
+ * triangle strips).
+ */
+ glProgramParameteriARB(Program, GL_GEOMETRY_INPUT_TYPE_ARB,
+ GL_POINTS);
+ glProgramParameteriARB(Program, GL_GEOMETRY_OUTPUT_TYPE_ARB,
+ GL_TRIANGLE_STRIP);
+ glProgramParameteriARB(Program,GL_GEOMETRY_VERTICES_OUT_ARB, 4);
+ CheckError(__LINE__);
+
+ glLinkProgramARB(Program);
+
+ /* check link */
+ {
+ GLint stat;
+ GetProgramiv(Program, GL_LINK_STATUS, &stat);
+ if (!stat) {
+ GLchar log[1000];
+ GLsizei len;
+ GetProgramInfoLog(Program, 1000, &len, log);
+ fprintf(stderr, "Shader link error:\n%s\n", log);
+ }
+ }
+
+ CheckError(__LINE__);
+
+ glUseProgram(Program);
+ CheckError(__LINE__);
+
+ uInverseViewportSize = glGetUniformLocation(Program, "InverseViewportSize");
+ uPointSize = glGetUniformLocation(Program, "PointSize");
+
+ glUniform1f(uPointSize, 24.0);
+
+ glClearColor(0.3f, 0.3f, 0.3f, 0.0f);
+
+ printf("GL_RENDERER = %s\n",(const char *) glGetString(GL_RENDERER));
+
+ assert(glIsProgram(Program));
+ assert(glIsShader(FragShader));
+ assert(glIsShader(VertShader));
+ assert(glIsShader(GeomShader));
+
+ glEnable(GL_DEPTH_TEST);
+
+ MakeTexture();
+ MakePoints();
+}
+
+
+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);
+ glutInitWindowSize(WinWidth, WinHeight);
+ glutInitDisplayMode(GLUT_RGB | GLUT_DEPTH | GLUT_DOUBLE);
+ Win = glutCreateWindow(argv[0]);
+ glewInit();
+ glutReshapeFunc(Reshape);
+ glutKeyboardFunc(Key);
+ glutDisplayFunc(Redisplay);
+ if (Anim)
+ glutIdleFunc(Idle);
+ ParseOptions(argc, argv);
+
+ Init();
+ glutMainLoop();
+ return 0;
+}
diff --git a/src/glsl/geom-wide-lines.c b/src/glsl/geom-wide-lines.c
new file mode 100644
index 0000000..85a18c0
--- /dev/null
+++ b/src/glsl/geom-wide-lines.c
@@ -0,0 +1,309 @@
+/**
+ * Test using a geometry shader to implement wide lines.
+ *
+ * Brian Paul
+ * March 2011
+ */
+
+#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"
+
+#ifndef M_PI
+#define M_PI 3.1415926535
+#endif
+
+static GLint WinWidth = 500, WinHeight = 500;
+static char *FragProgFile = NULL;
+static char *VertProgFile = NULL;
+static GLuint VertShader, GeomShader, FragShader;
+static GLuint Program;
+static GLint Win = 0;
+static GLboolean Anim = GL_TRUE;
+static GLfloat Xrot = 0, Yrot = 0;
+static int uLineWidth = -1, uInverseViewportSize = -1;
+
+static const int NumPoints = 50;
+static float Points[100][3], Colors[100][3];
+
+static const GLfloat Red[4] = {1, 0, 0, 1};
+static const GLfloat Green[4] = {0, 1, 0, 0};
+
+
+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
+Redisplay(void)
+{
+ int i;
+
+ glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
+
+ glPushMatrix();
+ glRotatef(Xrot, 1, 0, 0);
+ glRotatef(Yrot, 0, 0, 1);
+
+ glBegin(GL_LINES);
+ for (i = 0; i < NumPoints; i++) {
+ glColor3fv(Colors[i]);
+ glVertex3fv(Points[i]);
+ }
+ glEnd();
+
+ glPopMatrix();
+
+ glutSwapBuffers();
+}
+
+
+static void
+Idle(void)
+{
+ int curTime = glutGet(GLUT_ELAPSED_TIME);
+ Xrot = curTime * 0.02;
+ Yrot = curTime * 0.05;
+ glutPostRedisplay();
+}
+
+
+static void
+Reshape(int width, int height)
+{
+ float ar = (float) width / height;
+ glViewport(0, 0, width, height);
+ glMatrixMode(GL_PROJECTION);
+ glLoadIdentity();
+ glFrustum(-ar, ar, -1, 1, 3, 25);
+ glMatrixMode(GL_MODELVIEW);
+ glLoadIdentity();
+ glTranslatef(0, 0, -10);
+
+ {
+ GLfloat viewport[4];
+ glGetFloatv(GL_VIEWPORT, viewport);
+ glUniform2f(uInverseViewportSize, 1.0F / viewport[2], 1.0F / viewport[3]);
+ }
+}
+
+
+static void
+CleanUp(void)
+{
+ glDeleteShader(FragShader);
+ glDeleteShader(VertShader);
+ glDeleteShader(GeomShader);
+ glDeleteProgram(Program);
+ glutDestroyWindow(Win);
+}
+
+
+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 27:
+ CleanUp();
+ exit(0);
+ break;
+ }
+ glutPostRedisplay();
+}
+
+
+static void
+MakePoints(void)
+{
+ int i;
+ for (i = 0; i < NumPoints; i++) {
+ Colors[i][0] = (rand() % 1000) / 1000.0;
+ Colors[i][1] = (rand() % 1000) / 1000.0;
+ Colors[i][2] = (rand() % 1000) / 1000.0;
+ Points[i][0] = ((rand() % 2000) - 1000.0) / 500.0;
+ Points[i][1] = ((rand() % 2000) - 1000.0) / 500.0;
+ Points[i][2] = ((rand() % 2000) - 1000.0) / 500.0;
+ }
+}
+
+static void
+Init(void)
+{
+ static const char *fragShaderText =
+ "uniform sampler2D tex; \n"
+ "void main() \n"
+ "{ \n"
+ " gl_FragColor = gl_Color; \n"
+ "} \n";
+ static const char *vertShaderText =
+ "void main() \n"
+ "{ \n"
+ " gl_FrontColor = gl_Color; \n"
+ " gl_Position = ftransform(); \n"
+ "} \n";
+ static const char *geomShaderText =
+ "#version 120 \n"
+ "#extension GL_ARB_geometry_shader4: enable \n"
+ "uniform vec2 InverseViewportSize; \n"
+ "uniform float LineWidth; \n"
+ "void main() \n"
+ "{ \n"
+ " vec4 pos0 = gl_PositionIn[0]; \n"
+ " vec4 pos1 = gl_PositionIn[1]; \n"
+ " vec4 dir = abs(pos1 - pos0); \n"
+ " vec2 d0 = vec2(LineWidth * pos0.w) * InverseViewportSize; \n"
+ " vec2 d1 = vec2(LineWidth * pos1.w) * InverseViewportSize; \n"
+ " // this conditional could be avoided \n"
+ " if (dir.x > dir.y) { \n"
+ " // X-major line \n"
+ " d0.x = 0.0; \n"
+ " d1.x = 0.0; \n"
+ " } \n"
+ " else { \n"
+ " // Y-major line \n"
+ " d0.y = 0.0; \n"
+ " d1.y = 0.0; \n"
+ " } \n"
+ " gl_FrontColor = gl_FrontColorIn[0]; \n"
+ " gl_TexCoord[0] = vec4(0, 0, 0, 1); \n"
+ " gl_Position = pos0 + vec4( d0.x, -d0.y, 0, 0); \n"
+ " EmitVertex(); \n"
+ " gl_FrontColor = gl_FrontColorIn[1]; \n"
+ " gl_TexCoord[0] = vec4(1, 0, 0, 1); \n"
+ " gl_Position = pos1 + vec4( d1.x, -d1.y, 0, 0); \n"
+ " EmitVertex(); \n"
+ " gl_FrontColor = gl_FrontColorIn[0]; \n"
+ " gl_TexCoord[0] = vec4(0, 1, 0, 1); \n"
+ " gl_Position = pos0 + vec4(-d0.x, d0.y, 0, 0); \n"
+ " EmitVertex(); \n"
+ " gl_FrontColor = gl_FrontColorIn[1]; \n"
+ " gl_TexCoord[0] = vec4(1, 1, 0, 1); \n"
+ " gl_Position = pos1 + vec4(-d1.x, d1.y, 0, 0); \n"
+ " EmitVertex(); \n"
+ "} \n";
+
+ if (!ShadersSupported())
+ exit(1);
+
+ if (!glutExtensionSupported("GL_ARB_geometry_shader4")) {
+ fprintf(stderr, "Sorry, GL_ARB_geometry_shader4 is not supported.\n");
+ exit(1);
+ }
+
+ VertShader = CompileShaderText(GL_VERTEX_SHADER, vertShaderText);
+ FragShader = CompileShaderText(GL_FRAGMENT_SHADER, fragShaderText);
+ GeomShader = CompileShaderText(GL_GEOMETRY_SHADER_ARB, geomShaderText);
+ assert(GeomShader);
+
+ Program = LinkShaders3(VertShader, GeomShader, FragShader);
+ assert(Program);
+ CheckError(__LINE__);
+
+ /*
+ * The geometry shader will convert incoming points to quads (4-vertex
+ * triangle strips).
+ */
+ glProgramParameteriARB(Program, GL_GEOMETRY_INPUT_TYPE_ARB,
+ GL_LINES);
+ glProgramParameteriARB(Program, GL_GEOMETRY_OUTPUT_TYPE_ARB,
+ GL_TRIANGLE_STRIP);
+ glProgramParameteriARB(Program,GL_GEOMETRY_VERTICES_OUT_ARB, 4);
+ CheckError(__LINE__);
+
+ glLinkProgramARB(Program);
+
+ /* check link */
+ {
+ GLint stat;
+ GetProgramiv(Program, GL_LINK_STATUS, &stat);
+ if (!stat) {
+ GLchar log[1000];
+ GLsizei len;
+ GetProgramInfoLog(Program, 1000, &len, log);
+ fprintf(stderr, "Shader link error:\n%s\n", log);
+ }
+ }
+
+ CheckError(__LINE__);
+
+ glUseProgram(Program);
+ CheckError(__LINE__);
+
+ uInverseViewportSize = glGetUniformLocation(Program, "InverseViewportSize");
+ uLineWidth = glGetUniformLocation(Program, "LineWidth");
+
+ glUniform1f(uLineWidth, 12.0);
+
+ glClearColor(0.3f, 0.3f, 0.3f, 0.0f);
+
+ printf("GL_RENDERER = %s\n",(const char *) glGetString(GL_RENDERER));
+
+ assert(glIsProgram(Program));
+ assert(glIsShader(FragShader));
+ assert(glIsShader(VertShader));
+ assert(glIsShader(GeomShader));
+
+ glEnable(GL_DEPTH_TEST);
+
+ MakePoints();
+}
+
+
+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);
+ glutInitWindowSize(WinWidth, WinHeight);
+ glutInitDisplayMode(GLUT_RGB | GLUT_DEPTH | GLUT_DOUBLE);
+ Win = glutCreateWindow(argv[0]);
+ glewInit();
+ glutReshapeFunc(Reshape);
+ glutKeyboardFunc(Key);
+ glutDisplayFunc(Redisplay);
+ if (Anim)
+ glutIdleFunc(Idle);
+ ParseOptions(argc, argv);
+
+ Init();
+ glutMainLoop();
+ return 0;
+}
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