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-rw-r--r--progs/tests/mipmap_view.c241
1 files changed, 241 insertions, 0 deletions
diff --git a/progs/tests/mipmap_view.c b/progs/tests/mipmap_view.c
new file mode 100644
index 0000000000..d821f432f0
--- /dev/null
+++ b/progs/tests/mipmap_view.c
@@ -0,0 +1,241 @@
+/*
+ * Test mipmap generation and lod bias.
+ *
+ * Brian Paul
+ * 17 March 2008
+ */
+
+
+#include <assert.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <math.h>
+#include <GL/glut.h>
+#include <GL/glext.h>
+
+#include "readtex.h"
+
+#define TEXTURE_FILE "../images/arch.rgb"
+
+static int TexWidth = 256, TexHeight = 256;
+static int WinWidth = 1044, WinHeight = 900;
+static GLfloat Bias = 0.0;
+static GLboolean ScaleQuads = GL_FALSE;
+
+
+static void
+PrintString(const char *s)
+{
+ while (*s) {
+ glutBitmapCharacter(GLUT_BITMAP_8_BY_13, (int) *s);
+ s++;
+ }
+}
+
+
+static void
+Display(void)
+{
+ int x, y, bias;
+ char str[100];
+ int texWidth = TexWidth, texHeight = TexHeight;
+
+ glClear(GL_COLOR_BUFFER_BIT);
+
+ glMatrixMode(GL_PROJECTION);
+ glLoadIdentity();
+ glOrtho(0, WinWidth, 0, WinHeight, -1, 1);
+ glMatrixMode(GL_MODELVIEW);
+ glLoadIdentity();
+
+ glColor3f(1,1,1);
+
+ y = WinHeight - 300;
+ x = 4;
+
+ for (bias = -1; bias < 11; bias++) {
+
+ glRasterPos2f(x, y + TexHeight + 5);
+ sprintf(str, "Texture LOD Bias = %d", bias);
+ PrintString(str);
+
+ glPushMatrix();
+ glTranslatef(x, y, 0);
+
+ glEnable(GL_TEXTURE_2D);
+
+ if (ScaleQuads) {
+ if (bias > 0) {
+ texWidth = TexWidth >> bias;
+ texHeight = TexHeight >> bias;
+ if (texWidth < 1)
+ texWidth = 1;
+ if (texHeight < 1)
+ texHeight = 1;
+ }
+ glTexEnvf(GL_TEXTURE_FILTER_CONTROL_EXT, GL_TEXTURE_LOD_BIAS_EXT, 0.0);
+ }
+ else {
+ glTexEnvf(GL_TEXTURE_FILTER_CONTROL_EXT, GL_TEXTURE_LOD_BIAS_EXT, bias);
+ }
+
+ glBegin(GL_POLYGON);
+ glTexCoord2f(0, 0); glVertex2f(0, 0);
+ glTexCoord2f(1, 0); glVertex2f(texWidth, 0);
+ glTexCoord2f(1, 1); glVertex2f(texWidth, texHeight);
+ glTexCoord2f(0, 1); glVertex2f(0, texHeight);
+ glEnd();
+
+ glPopMatrix();
+
+ glDisable(GL_TEXTURE_2D);
+
+ x += TexWidth + 4;
+ if (x >= WinWidth) {
+ x = 4;
+ y -= 300;
+ }
+ }
+
+ glutSwapBuffers();
+}
+
+
+static void
+Reshape(int width, int height)
+{
+ WinWidth = width;
+ WinHeight = height;
+ glViewport(0, 0, width, height);
+}
+
+
+static void
+Key(unsigned char key, int x, int y)
+{
+ (void) x;
+ (void) y;
+ switch (key) {
+ case 'b':
+ Bias -= 10;
+ break;
+ case 'B':
+ Bias += 10;
+ break;
+ case '0':
+ case '1':
+ case '2':
+ case '3':
+ case '4':
+ case '5':
+ case '6':
+ case '7':
+ case '8':
+ case '9':
+ Bias = 100.0 * (key - '0');
+ break;
+ case 's':
+ ScaleQuads = !ScaleQuads;
+ break;
+ case 27:
+ exit(0);
+ break;
+ }
+ glutPostRedisplay();
+}
+
+
+static void
+Init(void)
+{
+ GLfloat maxBias;
+
+ if (!glutExtensionSupported("GL_EXT_texture_lod_bias")) {
+ printf("Sorry, GL_EXT_texture_lod_bias not supported by this renderer.\n");
+ exit(1);
+ }
+
+ if (!glutExtensionSupported("GL_SGIS_generate_mipmap")) {
+ printf("Sorry, GL_SGIS_generate_mipmap not supported by this renderer.\n");
+ exit(1);
+ }
+
+ glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
+
+ if (1) {
+ /* test auto mipmap generation */
+ GLint width, height, i;
+ GLenum format;
+ GLubyte *image = LoadRGBImage(TEXTURE_FILE, &width, &height, &format);
+ if (!image) {
+ printf("Error: could not load texture image %s\n", TEXTURE_FILE);
+ exit(1);
+ }
+ /* resize to TexWidth x TexHeight */
+ if (width != TexWidth || height != TexHeight) {
+ GLubyte *newImage = malloc(TexWidth * TexHeight * 4);
+ gluScaleImage(format, width, height, GL_UNSIGNED_BYTE, image,
+ TexWidth, TexHeight, GL_UNSIGNED_BYTE, newImage);
+ free(image);
+ image = newImage;
+ }
+ printf("Using GL_SGIS_generate_mipmap\n");
+ glTexParameteri(GL_TEXTURE_2D, GL_GENERATE_MIPMAP_SGIS, GL_TRUE);
+ glTexImage2D(GL_TEXTURE_2D, 0, format, TexWidth, TexHeight, 0,
+ format, GL_UNSIGNED_BYTE, image);
+ free(image);
+
+ /* make sure mipmap was really generated correctly */
+ width = TexWidth;
+ height = TexHeight;
+ for (i = 0; i < 9; i++) {
+ GLint w, h;
+ glGetTexLevelParameteriv(GL_TEXTURE_2D, i, GL_TEXTURE_WIDTH, &w);
+ glGetTexLevelParameteriv(GL_TEXTURE_2D, i, GL_TEXTURE_HEIGHT, &h);
+ printf("Level %d size: %d x %d\n", i, w, h);
+ assert(w == width);
+ assert(h == height);
+ width /= 2;
+ height /= 2;
+ }
+ }
+ else {
+ if (LoadRGBMipmaps(TEXTURE_FILE, GL_RGB)) {
+ printf("Using gluBuildMipmaps()\n");
+ }
+ else {
+ printf("Error: could not load texture image %s\n", TEXTURE_FILE);
+ exit(1);
+ }
+ }
+
+
+ /* mipmapping required for this extension */
+ glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);
+ glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+ glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
+
+ glGetFloatv(GL_MAX_TEXTURE_LOD_BIAS_EXT, &maxBias);
+
+ printf("GL_RENDERER: %s\n", (char*) glGetString(GL_RENDERER));
+ printf("LOD bias range: [%g, %g]\n", -maxBias, maxBias);
+
+ printf("Press 's' to toggle quad scaling\n");
+}
+
+
+int
+main(int argc, char *argv[])
+{
+ glutInit(&argc, argv);
+ glutInitWindowPosition(0, 0);
+ glutInitWindowSize(WinWidth, WinHeight);
+ glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE);
+ glutCreateWindow(argv[0]);
+ glutReshapeFunc(Reshape);
+ glutKeyboardFunc(Key);
+ glutDisplayFunc(Display);
+ Init();
+ glutMainLoop();
+ return 0;
+}