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-rw-r--r--progs/trivial/.gitignore1
-rw-r--r--progs/trivial/Makefile1
-rw-r--r--progs/trivial/SConscript3
-rw-r--r--progs/trivial/clear-fbo-scissor.c234
-rw-r--r--progs/trivial/tri-stencil.c3
5 files changed, 241 insertions, 1 deletions
diff --git a/progs/trivial/.gitignore b/progs/trivial/.gitignore
index caf930d9212..2b42f042896 100644
--- a/progs/trivial/.gitignore
+++ b/progs/trivial/.gitignore
@@ -1,5 +1,6 @@
clear
clear-fbo
+clear-fbo-scissor
clear-fbo-tex
clear-random
clear-repeat
diff --git a/progs/trivial/Makefile b/progs/trivial/Makefile
index b4a903cb68f..a10748f9487 100644
--- a/progs/trivial/Makefile
+++ b/progs/trivial/Makefile
@@ -11,6 +11,7 @@ include $(TOP)/configs/current
LIBS = -L$(TOP)/$(LIB_DIR) -l $(GLEW_LIB) -l$(GLUT_LIB) -l$(GLU_LIB) -l$(GL_LIB) $(APP_LIB_DEPS)
SOURCES = \
+ clear-fbo-scissor.c \
clear-fbo-tex.c \
clear-fbo.c \
clear-scissor.c \
diff --git a/progs/trivial/SConscript b/progs/trivial/SConscript
index f480da047eb..24b4f91fb0a 100644
--- a/progs/trivial/SConscript
+++ b/progs/trivial/SConscript
@@ -1,7 +1,8 @@
Import('*')
progs = [
- 'clear-fbo-tex',
+ 'clear-fbo-scissor',
+ 'clear-fbo-tex',
'clear-fbo',
'clear-scissor',
'clear-undefined',
diff --git a/progs/trivial/clear-fbo-scissor.c b/progs/trivial/clear-fbo-scissor.c
new file mode 100644
index 00000000000..6a605e16a8b
--- /dev/null
+++ b/progs/trivial/clear-fbo-scissor.c
@@ -0,0 +1,234 @@
+/*
+ * Use scissor to clear the four quadrants of the FBO to different
+ * colors. Then draw a grey triangle in the middle.
+ */
+
+
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <math.h>
+#include <string.h>
+#include <GL/glew.h>
+#include <GL/glut.h>
+#include <GL/glu.h>
+
+
+static int Width = 512, Height = 512;
+static GLuint MyFB, MyRB;
+static GLboolean UseTex = GL_FALSE;
+static GLboolean UseCopyPix = GL_FALSE;
+
+
+#define CheckError() \
+ do { \
+ GLenum err = glGetError(); \
+ if (err != GL_NO_ERROR) \
+ printf("Error: %s\n", gluErrorString(err)); \
+ assert(err == GL_NO_ERROR); \
+ } while (0)
+
+
+static void
+Init(void)
+{
+ GLenum status;
+
+ 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));
+ fflush(stderr);
+
+ if (!glutExtensionSupported("GL_EXT_framebuffer_object")) {
+ printf("GL_EXT_framebuffer_object not found!\n");
+ exit(0);
+ }
+
+ glGenFramebuffersEXT(1, &MyFB);
+ glGenRenderbuffersEXT(1, &MyRB);
+
+ glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, MyFB);
+
+ if (UseTex) {
+ GLuint tex;
+ glGenTextures(1, &tex);
+ glBindTexture(GL_TEXTURE_2D, tex);
+ glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, Width, Height, 0,
+ GL_RGBA, GL_UNSIGNED_BYTE, NULL);
+ glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+ glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+ glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT,
+ GL_COLOR_ATTACHMENT0_EXT,
+ GL_TEXTURE_2D, tex, 0);
+ }
+ else {
+ glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, MyRB);
+
+ glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT,
+ GL_COLOR_ATTACHMENT0_EXT,
+ GL_RENDERBUFFER_EXT, MyRB);
+
+ glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT, GL_RGB, Width, Height);
+ }
+
+ status = glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT);
+ if (status != GL_FRAMEBUFFER_COMPLETE_EXT) {
+ fprintf(stderr, "Framebuffer object is incomplete (0x%x)!\n", status);
+ }
+
+ glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
+}
+
+
+static void
+Reshape(int width, int height)
+{
+ glViewport(0, 0, width, height);
+ glMatrixMode(GL_PROJECTION);
+ glLoadIdentity();
+ glOrtho(-1.0, 1.0, -1.0, 1.0, -1.0, 1.0);
+ glMatrixMode(GL_MODELVIEW);
+
+ Width = width;
+ Height = height;
+ if (!UseTex) {
+ glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT, GL_RGB, Width, Height);
+ }
+}
+
+
+static void
+Key(unsigned char key, int x, int y)
+{
+ if (key == 27) {
+ exit(0);
+ }
+ glutPostRedisplay();
+}
+
+
+static void
+Draw(void)
+{
+ GLboolean scissor = GL_TRUE;
+
+ /* draw to user framebuffer */
+ glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, MyFB);
+ glDrawBuffer(GL_COLOR_ATTACHMENT0_EXT);
+ glReadBuffer(GL_COLOR_ATTACHMENT0_EXT);
+
+ glViewport(0, 0, Width, Height);
+ CheckError();
+
+ if (scissor) {
+ glEnable(GL_SCISSOR_TEST);
+
+ /* lower-left = red */
+ glClearColor(1, 0, 0, 0);
+ glScissor(0, 0, Width / 2, Height / 2);
+ glClear(GL_COLOR_BUFFER_BIT);
+
+ /* lower-right = green */
+ glClearColor(0, 1, 0, 0);
+ glScissor(Width / 2, 0, Width - Width / 2, Height / 2);
+ glClear(GL_COLOR_BUFFER_BIT);
+
+ /* upper-left = blue */
+ glClearColor(0, 0, 1, 0);
+ glScissor(0, Height / 2, Width / 2, Height - Height / 2);
+ glClear(GL_COLOR_BUFFER_BIT);
+
+ /* upper-right = white */
+ glClearColor(1, 1, 1, 0);
+ glScissor(Width / 2, Height / 2, Width - Width / 2, Height - Height / 2);
+ glClear(GL_COLOR_BUFFER_BIT);
+
+ glDisable(GL_SCISSOR_TEST);
+ }
+ else {
+ glClearColor(0, 1, 0, 0);
+ glClear(GL_COLOR_BUFFER_BIT);
+ }
+
+ CheckError();
+
+ /* gray triangle in middle, pointing up */
+ glColor3f(0.5, 0.5, 0.5);
+ glBegin(GL_TRIANGLES);
+ glVertex2f(Width/4, Height/4);
+ glVertex2f(Width*3/4, Height/4);
+ glVertex2f(Width/2, Height*3/4);
+ glVertex2f(-0.5, -0.5);
+ glVertex2f(+0.5, -0.5);
+ glVertex2f( 0.0, 0.7);
+ glEnd();
+
+ CheckError();
+
+ /* copy fbo to window */
+ glBindFramebufferEXT(GL_READ_FRAMEBUFFER_EXT, MyFB);
+ glReadBuffer(GL_COLOR_ATTACHMENT0_EXT);
+ glBindFramebufferEXT(GL_DRAW_FRAMEBUFFER_EXT, 0);
+ glDrawBuffer(GL_BACK);
+
+ if (UseCopyPix) {
+ glWindowPos2i(0, 0);
+ glCopyPixels(0, 0, Width, Height, GL_COLOR);
+ }
+ else {
+ GLubyte *buffer = malloc(Width * Height * 4);
+
+ /* read from user framebuffer */
+ glReadPixels(0, 0, Width, Height, GL_RGBA, GL_UNSIGNED_BYTE, buffer);
+
+ /* draw to window */
+ glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
+ glWindowPos2iARB(0, 0);
+ glDrawPixels(Width, Height, GL_RGBA, GL_UNSIGNED_BYTE, buffer);
+
+ free(buffer);
+ }
+
+ /* Bind normal framebuffer */
+ glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
+
+ glutSwapBuffers();
+
+ CheckError();
+}
+
+
+int
+main(int argc, char *argv[])
+{
+ int i;
+
+ glutInit(&argc, argv);
+ glutInitWindowPosition(100, 0);
+ glutInitWindowSize(Width, Height);
+ glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE);
+
+ for (i = 1; i < argc; i++) {
+ if (strcmp(argv[i], "-t") == 0)
+ UseTex = GL_TRUE;
+ else if (strcmp(argv[i], "-c") == 0)
+ UseCopyPix = GL_TRUE;
+ }
+
+ if (UseTex)
+ printf("Using render to texture\n");
+ else
+ printf("Using user-created render buffer\n");
+
+ if (!glutCreateWindow(argv[0])) {
+ exit(1);
+ }
+
+ glewInit();
+ Init();
+ glutReshapeFunc(Reshape);
+ glutKeyboardFunc(Key);
+ glutDisplayFunc(Draw);
+ glutMainLoop();
+ return 0;
+}
diff --git a/progs/trivial/tri-stencil.c b/progs/trivial/tri-stencil.c
index 9f68bca9149..d66b68c415a 100644
--- a/progs/trivial/tri-stencil.c
+++ b/progs/trivial/tri-stencil.c
@@ -77,6 +77,7 @@ static void Draw(void)
glStencilFunc(GL_ALWAYS, 1, 1);
glStencilOp(GL_KEEP, GL_KEEP, GL_REPLACE);
+ /* red triangle (setting stencil to 1) */
glColor3ub(200, 0, 0);
glBegin(GL_POLYGON);
glVertex3i(-4, -4, 0);
@@ -88,6 +89,7 @@ static void Draw(void)
glStencilFunc(GL_EQUAL, 1, 1);
glStencilOp(GL_INCR, GL_KEEP, GL_DECR);
+ /* green quad (if over red, decr stencil to 0, else incr to 1) */
glColor3ub(0, 200, 0);
glBegin(GL_POLYGON);
glVertex3i(3, 3, 0);
@@ -101,6 +103,7 @@ static void Draw(void)
glStencilFunc(GL_EQUAL, 1, 1);
glStencilOp(GL_KEEP, GL_KEEP, GL_KEEP);
+ /* blue quad (where stencil == 1) */
glColor3ub(0, 0, 200);
glBegin(GL_POLYGON);
glVertex3f(2.5, 2.5, 0);
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-19 12:11:19 +0000