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-rw-r--r--progs/trivial/Makefile1
-rw-r--r--progs/trivial/readpixels.c88
2 files changed, 89 insertions, 0 deletions
diff --git a/progs/trivial/Makefile b/progs/trivial/Makefile
index 80f2b752cd..82769e817a 100644
--- a/progs/trivial/Makefile
+++ b/progs/trivial/Makefile
@@ -46,6 +46,7 @@ SOURCES = \
quads.c \
quadstrip.c \
quadstrip-flat.c \
+ readpixels.c \
dlist-edgeflag.c \
dlist-dangling.c \
dlist-edgeflag-dangling.c \
diff --git a/progs/trivial/readpixels.c b/progs/trivial/readpixels.c
new file mode 100644
index 0000000000..b1f04f81d9
--- /dev/null
+++ b/progs/trivial/readpixels.c
@@ -0,0 +1,88 @@
+/*
+ * glRead/DrawPixels test
+ */
+
+
+#define GL_GLEXT_PROTOTYPES
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <GL/glut.h>
+
+static int Width = 250, Height = 250;
+
+static void Init(void)
+{
+ 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));
+ glClearColor(0.3, 0.1, 0.3, 0.0);
+}
+
+static void Reshape(int width, int height)
+{
+ Width = width / 2;
+ Height = height;
+ /* draw on left half (we'll read that area) */
+ glViewport(0, 0, Width, height);
+ glMatrixMode(GL_PROJECTION);
+ glLoadIdentity();
+ glOrtho(-1.0, 1.0, -1.0, 1.0, -0.5, 1000.0);
+ glMatrixMode(GL_MODELVIEW);
+}
+
+static void Key(unsigned char key, int x, int y)
+{
+ switch (key) {
+ case 27:
+ exit(0);
+ default:
+ return;
+ }
+ glutPostRedisplay();
+}
+
+static void Draw(void)
+{
+ GLfloat *image = (GLfloat *) malloc(Width * Height * 4 * sizeof(GLfloat));
+
+ glClear(GL_COLOR_BUFFER_BIT);
+
+ glBegin(GL_TRIANGLES);
+ glColor3f(.8,0,0);
+ glVertex3f(-0.9, -0.9, -30.0);
+ glColor3f(0,.9,0);
+ glVertex3f( 0.9, -0.9, -30.0);
+ glColor3f(0,0,.7);
+ glVertex3f( 0.0, 0.9, -30.0);
+ glEnd();
+
+ glReadPixels(0, 0, Width, Height, GL_RGBA, GL_FLOAT, image);
+ printf("Pixel(0,0) = %f, %f, %f, %f\n",
+ image[0], image[1], image[2], image[3]);
+ /* draw to right half of window */
+ glWindowPos2iARB(Width, 0);
+ glDrawPixels(Width, Height, GL_RGBA, GL_FLOAT, image);
+ free(image);
+
+ glutSwapBuffers();
+}
+
+int main(int argc, char **argv)
+{
+ glutInit(&argc, argv);
+ glutInitWindowPosition(0, 0);
+ glutInitWindowSize(Width*2, Height);
+ glutInitDisplayMode(GLUT_RGB | GLUT_ALPHA | GLUT_DOUBLE);
+ if (glutCreateWindow(argv[0]) == GL_FALSE) {
+ exit(1);
+ }
+
+ Init();
+
+ glutReshapeFunc(Reshape);
+ glutKeyboardFunc(Key);
+ glutDisplayFunc(Draw);
+ glutMainLoop();
+ return 0;
+}