From b5d3c17427646b51f341f6bc6bba160d6dc686c2 Mon Sep 17 00:00:00 2001
From: Brian Paul <brianp@vmware.com>
Date: Wed, 4 Mar 2009 21:03:29 -0700
Subject: tests: add new mapbufrange.c test to test GL_ARB_map_buffer_range

This only tests the most basic functionality for now.
---
 progs/tests/mapbufrange.c | 204 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 204 insertions(+)
 create mode 100644 progs/tests/mapbufrange.c

(limited to 'progs/tests/mapbufrange.c')

diff --git a/progs/tests/mapbufrange.c b/progs/tests/mapbufrange.c
new file mode 100644
index 00000000000..04d57b58f1b
--- /dev/null
+++ b/progs/tests/mapbufrange.c
@@ -0,0 +1,204 @@
+/*
+ * Test glMapBuffer() and glMapBufferRange()
+ *
+ * Fill a VBO with vertex data to draw several colored quads.
+ * On each redraw, update the geometry for just one rect in the VBO.
+ *
+ * Brian Paul
+ * 4 March 2009
+ */
+
+
+#define GL_GLEXT_PROTOTYPES
+#include <assert.h>
+#include <math.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <GL/glew.h>
+#include <GL/glut.h>
+
+static GLuint Win;
+static const GLuint NumRects = 10;
+static GLuint BufferID;
+static GLboolean Anim = GL_TRUE;
+static GLboolean UseBufferRange = GL_FALSE;
+
+
+
+static const float RectData[] = {
+   /* vertex */    /* color */
+    0, -1, 0,      1,  0,  0,
+    1,  0, 0,      1,  1,  0,
+    0,  1, 0,      0,  1,  1,
+   -1,  0, 0,      1,  0,  1
+};
+
+
+/**
+ * The buffer contains vertex positions (float[3]) and colors (float[3])
+ * for 'NumRects' quads.
+ * This function updates/rotates one quad in the buffer.
+ */
+static void
+UpdateRect(int r, float angle)
+{
+   float *rect;
+   int i;
+
+   assert(r < NumRects);
+
+   glBindBufferARB(GL_ARRAY_BUFFER_ARB, BufferID);
+   if (UseBufferRange) {
+      GLintptr offset = r * sizeof(RectData);
+      GLsizeiptr length = sizeof(RectData);
+      GLbitfield access = GL_MAP_WRITE_BIT | GL_MAP_INVALIDATE_RANGE_BIT;
+      float *buf = (float *) glMapBufferRange(GL_ARRAY_BUFFER_ARB,
+                                              offset, length, access);
+      rect = buf;
+   }
+   else {
+      /* map whole buffer */
+      float *buf = (float *)
+         glMapBufferARB(GL_ARRAY_BUFFER_ARB, GL_WRITE_ONLY_ARB);
+      rect = buf + r * 24;
+   }
+
+   /* set rect verts/colors */
+   memcpy(rect, RectData, sizeof(RectData));
+
+   /* loop over four verts, updating vertices */
+   for (i = 0; i < 4; i++) {
+      float x = 0.2 * RectData[i*6+0];
+      float y = 0.2 * RectData[i*6+1];
+      float xpos = -2.5 + 0.5 * r;
+      float ypos = 0.0;
+
+      /* translate and rotate vert */
+      rect[i * 6 + 0] = xpos + x * cos(angle) + y * sin(angle);
+      rect[i * 6 + 1] = ypos + x * sin(angle) - y * cos(angle);
+   }
+
+   glUnmapBufferARB(GL_ARRAY_BUFFER_ARB);
+}
+
+
+static void
+LoadBuffer(void)
+{
+   static int frame = 0;
+   float angle = glutGet(GLUT_ELAPSED_TIME) * 0.001;
+   UpdateRect(frame % NumRects, angle);
+   frame++;
+}
+
+
+static void
+Draw(void)
+{
+   glBindBufferARB(GL_ARRAY_BUFFER_ARB, BufferID);
+   glVertexPointer(3, GL_FLOAT, 24, 0);
+   glEnable(GL_VERTEX_ARRAY);
+
+   glColorPointer(3, GL_FLOAT, 24, (void*) 12);
+   glEnable(GL_COLOR_ARRAY);
+
+   glDrawArrays(GL_QUADS, 0, NumRects * 4);
+
+   if (0)
+      glFinish();
+}
+
+
+static void
+Display(void)
+{
+   glClear(GL_COLOR_BUFFER_BIT);
+   Draw();
+   glutSwapBuffers();
+}
+
+
+static void
+Reshape(int width, int height)
+{
+   glViewport(0, 0, width, height);
+   glMatrixMode(GL_PROJECTION);
+   glLoadIdentity();
+   glOrtho(-3.0, 3.0, -1.0, 1.0, -1.0, 1.0);
+   glMatrixMode(GL_MODELVIEW);
+   glLoadIdentity();
+}
+
+
+static void
+Idle(void)
+{
+   LoadBuffer();
+   glutPostRedisplay();
+}
+
+
+static void
+Key(unsigned char key, int x, int y)
+{
+   (void) x;
+   (void) y;
+   if (key == 'a') {
+      Anim = !Anim;
+      glutIdleFunc(Anim ? Idle : NULL);
+   }
+   else if (key == 's') {
+      LoadBuffer();
+   }
+   else if (key == 27) {
+      glutDestroyWindow(Win);
+      exit(0);
+   }
+   glutPostRedisplay();
+}
+
+
+static void
+Init(void)
+{
+   GLuint BufferSize = NumRects * sizeof(RectData);
+   float *buf;
+
+   if (!glutExtensionSupported("GL_ARB_vertex_buffer_object")) {
+      printf("GL_ARB_vertex_buffer_object not found!\n");
+      exit(0);
+   }
+
+   UseBufferRange = glutExtensionSupported("GL_ARB_map_buffer_range");
+   printf("Use GL_ARB_map_buffer_range: %c\n", "NY"[UseBufferRange]);
+
+   printf("GL_RENDERER = %s\n", (char *) glGetString(GL_RENDERER));
+
+   /* initially load buffer with zeros */
+   buf = (float *) calloc(1, BufferSize);
+
+   glGenBuffersARB(1, &BufferID);
+   glBindBufferARB(GL_ARRAY_BUFFER_ARB, BufferID);
+   glBufferDataARB(GL_ARRAY_BUFFER_ARB, BufferSize, buf, GL_DYNAMIC_DRAW_ARB);
+
+   free(buf);
+}
+
+
+int
+main(int argc, char *argv[])
+{
+   glutInit(&argc, argv);
+   glutInitWindowSize(800, 200);
+   glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE);
+   Win = glutCreateWindow(argv[0]);
+   glewInit();
+   glutReshapeFunc(Reshape);
+   glutKeyboardFunc(Key);
+   glutDisplayFunc(Display);
+   glutIdleFunc(Anim ? Idle : NULL);
+   Init();
+   glutMainLoop();
+   return 0;
+}
-- 
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