diff options
Diffstat (limited to 'progs/tests/minmag.c')
| -rw-r--r-- | progs/tests/minmag.c | 198 |
1 files changed, 198 insertions, 0 deletions
diff --git a/progs/tests/minmag.c b/progs/tests/minmag.c new file mode 100644 index 00000000000..78ef9db03ac --- /dev/null +++ b/progs/tests/minmag.c @@ -0,0 +1,198 @@ +/* + * Test minification vs. magnification filtering. + * Draw two quads with different filtering modes: + * + * +--------------------------+ +--------------------------+ + * | MagFilter = GL_LINEAR | | MagFilter = GL_LINEAR | + * | MinFilter = GL_LINEAR | | MinFilter = GL_NEAREST | + * +--------------------------+ +--------------------------+ + * + * They should look different when the quad is smaller than the level 0 + * texture size (when minifying). + */ + +#include <assert.h> +#include <math.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> +#include <GL/glut.h> + + +static GLint Width = 1000, Height = 500; + + +static GLint TexWidth = 256, TexHeight = 256; +static GLfloat Zpos = 5; +static GLboolean MipMap = 0*GL_TRUE; +static GLboolean LinearFilter = GL_TRUE; + + +static void +redraw(void) +{ + GLfloat w = 1.0; + GLfloat h = 1.0; + + glClear( GL_COLOR_BUFFER_BIT ); + + glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR); + + glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR); + + glPushMatrix(); + glTranslatef(-1.5, 0, -Zpos); + glBegin(GL_POLYGON); + glTexCoord2f(0, 0); glVertex2f(-w, -h); + glTexCoord2f(1, 0); glVertex2f( w, -h); + glTexCoord2f(1, 1); glVertex2f( w, h); + glTexCoord2f(0, 1); glVertex2f(-w, h); + glEnd(); + glPopMatrix(); + + glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST); + + glPushMatrix(); + glTranslatef(1.5, 0, -Zpos); + glBegin(GL_POLYGON); + glTexCoord2f(0, 0); glVertex2f(-w, -h); + glTexCoord2f(1, 0); glVertex2f( w, -h); + glTexCoord2f(1, 1); glVertex2f( w, h); + glTexCoord2f(0, 1); glVertex2f(-w, h); + glEnd(); + glPopMatrix(); + + glutSwapBuffers(); +} + + +static void +init(void) +{ + GLubyte color[10][4] = { + { 0, 0, 0, 0 }, + { 1, 0, 0, 0 }, + { 0, 1, 0, 0 }, + { 0, 0, 1, 0 }, + { 0, 1, 1, 0 }, + { 1, 0, 1, 0 }, + { 1, 1, 0, 0 }, + { 1, 0, 0, 0 }, + { 0, 1, 0, 0 }, + { 0, 0, 1, 0 } + }; + GLubyte *texImage; + + printf("GL_RENDERER = %s\n", (char *) glGetString(GL_RENDERER)); + printf("Left quad should be linear filtered and right should be nearest filtered.\n"); + printf("Press z/Z to change quad distance.\n"); + + texImage = (GLubyte*) malloc(4 * TexWidth * TexHeight * sizeof(GLubyte)); + assert(texImage); + + { + GLint level = 0; + GLint w = TexWidth, h = TexHeight; + while (1) { + int i, j; + + for (i = 0; i < h; i++) { + for (j = 0;j < w; j++) { + if (w==1 || h==1 || (((i / 2) ^ (j / 2)) & 1)) { + /*if (j < i) {*/ + texImage[(i*w+j) * 4 + 0] = 255; + texImage[(i*w+j) * 4 + 1] = 255; + texImage[(i*w+j) * 4 + 2] = 255; + texImage[(i*w+j) * 4 + 3] = 255; + } + else { + texImage[(i*w+j) * 4 + 0] = color[level][0] * 255; + texImage[(i*w+j) * 4 + 1] = color[level][1] * 255; + texImage[(i*w+j) * 4 + 2] = color[level][2] * 255; + texImage[(i*w+j) * 4 + 3] = color[level][3] * 255; + } + } + } + + glTexImage2D(GL_TEXTURE_2D, level, GL_RGBA8, w, h, 0, + GL_RGBA, GL_UNSIGNED_BYTE, texImage); + + printf("Texture level %d: %d x %d\n", level, w, h); + if (!MipMap) + break; + + if (w == 1 && h == 1) + break; + if (w > 1) + w /= 2; + if (h > 1) + h /= 2; + level++; + } + } + + free(texImage); + + glClearColor(0.25, 0.25, 0.25, 1.0); + glEnable(GL_TEXTURE_2D); + + glViewport(0, 0, Width, Height); +} + + + +static void +Reshape(int width, int height) +{ + float ar = (float) width /height; + Width = width; + Height = height; + glViewport(0, 0, width, height); + glMatrixMode(GL_PROJECTION); + glLoadIdentity(); + glFrustum(-ar, ar, -1.0, 1.0, 5.0, 2500.0); + glMatrixMode(GL_MODELVIEW); + glLoadIdentity(); + glTranslatef(0.0, 0.0, -15.0); +} + + +static void +Key(unsigned char key, int x, int y) +{ + (void) x; + (void) y; + switch (key) { + case 'z': + Zpos--; + break; + case 'Z': + Zpos++; + break; + case 'f': + LinearFilter = !LinearFilter; + break; + case 27: + exit(0); + break; + } + glutPostRedisplay(); +} + + +int +main(int argc, char *argv[]) +{ + glutInit(&argc, argv); + glutInitWindowPosition(0, 0); + glutInitWindowSize(Width, Height); + glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH); + glutCreateWindow(argv[0]); + glutReshapeFunc(Reshape); + glutKeyboardFunc(Key); + glutDisplayFunc(redraw); + init(); + glutMainLoop(); + return 0; +} |