Initial revision
This commit is contained in:
jtg
295
progs/samples/blendeq.c
Normal file
295
progs/samples/blendeq.c
Normal file
@@ -0,0 +1,295 @@
|
||||
/*
|
||||
** blendeq.c - Demonstrates the use of the blend_minmax, blend_subtract,
|
||||
** and blend_logic_op extensions using glBlendEquationEXT.
|
||||
**
|
||||
** Over a two-color backround, draw rectangles using twelve blend
|
||||
** options. The values are read back as UNSIGNED_BYTE and printed
|
||||
** in hex over each value. These values are useful for logic
|
||||
** op comparisons when channels are 8 bits deep.
|
||||
*/
|
||||
|
||||
#include <string.h>
|
||||
#include <stdlib.h>
|
||||
#include <stdio.h>
|
||||
#include <GL/glut.h>
|
||||
|
||||
|
||||
GLenum doubleBuffer;
|
||||
static int dithering = 0;
|
||||
static int doPrint = 1;
|
||||
static int deltaY;
|
||||
GLint windW, windH;
|
||||
|
||||
static void DrawString(const char *string)
|
||||
{
|
||||
int i;
|
||||
|
||||
for (i = 0; string[i]; i++)
|
||||
glutBitmapCharacter(GLUT_BITMAP_9_BY_15, string[i]);
|
||||
}
|
||||
|
||||
static void Init(void)
|
||||
{
|
||||
|
||||
glDisable(GL_DITHER);
|
||||
glShadeModel(GL_FLAT);
|
||||
}
|
||||
|
||||
static void Reshape(int width, int height)
|
||||
{
|
||||
|
||||
windW = (GLint)width;
|
||||
windH = (GLint)height;
|
||||
|
||||
glViewport(0, 0, (GLint)width, (GLint)height);
|
||||
deltaY = windH /16;
|
||||
|
||||
glMatrixMode(GL_PROJECTION);
|
||||
glLoadIdentity();
|
||||
gluOrtho2D(0, windW, 0, windH);
|
||||
glMatrixMode(GL_MODELVIEW);
|
||||
}
|
||||
|
||||
static void Key(unsigned char key, int x, int y)
|
||||
{
|
||||
|
||||
switch (key) {
|
||||
case 27:
|
||||
exit(1);
|
||||
case 'd':
|
||||
dithering = !dithering;
|
||||
break;
|
||||
default:
|
||||
return;
|
||||
}
|
||||
|
||||
glutPostRedisplay();
|
||||
}
|
||||
|
||||
static void PrintColorStrings( void )
|
||||
{
|
||||
GLubyte ubbuf[3];
|
||||
int i, xleft, xright;
|
||||
char colorString[18];
|
||||
|
||||
xleft = 5 + windW/4;
|
||||
xright = 5 + windW/2;
|
||||
|
||||
for (i = windH - deltaY + 4; i > 0; i-=deltaY) {
|
||||
glReadPixels(xleft, i+10, 1, 1, GL_RGB, GL_UNSIGNED_BYTE, ubbuf);
|
||||
sprintf(colorString, "(0x%x, 0x%x, 0x%x)",
|
||||
ubbuf[0], ubbuf[1], ubbuf[2]);
|
||||
glRasterPos2f(xleft, i);
|
||||
DrawString(colorString);
|
||||
glReadPixels(xright, i+10, 1, 1, GL_RGB, GL_UNSIGNED_BYTE, ubbuf);
|
||||
sprintf(colorString, "(0x%x, 0x%x, 0x%x)",
|
||||
ubbuf[0], ubbuf[1], ubbuf[2]);
|
||||
glRasterPos2f(xright, i);
|
||||
DrawString(colorString);
|
||||
}
|
||||
}
|
||||
|
||||
static void Draw(void)
|
||||
{
|
||||
int stringOffset = 5, stringx = 8;
|
||||
int x1, x2, xleft, xright;
|
||||
int i;
|
||||
|
||||
(dithering) ? glEnable(GL_DITHER) : glDisable(GL_DITHER);
|
||||
glDisable(GL_BLEND);
|
||||
|
||||
glClearColor(0.5, 0.6, 0.1, 1.0);
|
||||
glClear(GL_COLOR_BUFFER_BIT);
|
||||
|
||||
/* Draw background */
|
||||
glColor3f(0.1, 0.1, 1.0);
|
||||
glRectf(0.0, 0.0, windW/2, windH);
|
||||
|
||||
/* Draw labels */
|
||||
glColor3f(0.8, 0.8, 0.0);
|
||||
i = windH - deltaY + stringOffset;
|
||||
glRasterPos2f(stringx, i); i -= deltaY;
|
||||
DrawString("SOURCE");
|
||||
glRasterPos2f(stringx, i); i -= deltaY;
|
||||
DrawString("DEST");
|
||||
glRasterPos2f(stringx, i); i -= deltaY;
|
||||
DrawString("min");
|
||||
glRasterPos2f(stringx, i); i -= deltaY;
|
||||
DrawString("max");
|
||||
glRasterPos2f(stringx, i); i -= deltaY;
|
||||
DrawString("subtract");
|
||||
glRasterPos2f(stringx, i); i -= deltaY;
|
||||
DrawString("reverse_subtract");
|
||||
glRasterPos2f(stringx, i); i -= deltaY;
|
||||
DrawString("clear");
|
||||
glRasterPos2f(stringx, i); i -= deltaY;
|
||||
DrawString("set");
|
||||
glRasterPos2f(stringx, i); i -= deltaY;
|
||||
DrawString("copy");
|
||||
glRasterPos2f(stringx, i); i -= deltaY;
|
||||
DrawString("noop");
|
||||
glRasterPos2f(stringx, i); i -= deltaY;
|
||||
DrawString("and");
|
||||
glRasterPos2f(stringx, i); i -= deltaY;
|
||||
DrawString("invert");
|
||||
glRasterPos2f(stringx, i); i -= deltaY;
|
||||
DrawString("or");
|
||||
glRasterPos2f(stringx, i); i -= deltaY;
|
||||
DrawString("xor");
|
||||
|
||||
|
||||
i = windH - deltaY;
|
||||
x1 = windW/4;
|
||||
x2 = 3 * windW/4;
|
||||
xleft = 5 + windW/4;
|
||||
xright = 5 + windW/2;
|
||||
|
||||
/* Draw foreground color for comparison */
|
||||
glColor3f(0.9, 0.2, 0.8);
|
||||
glRectf(x1, i, x2, i+deltaY);
|
||||
|
||||
/* Leave one rectangle of background color */
|
||||
|
||||
/* Begin test cases */
|
||||
glEnable(GL_BLEND);
|
||||
glBlendFunc(GL_ONE, GL_ONE);
|
||||
|
||||
i -= 2*deltaY;
|
||||
glBlendEquationEXT(GL_MIN_EXT);
|
||||
glRectf(x1, i, x2, i+deltaY);
|
||||
|
||||
i -= deltaY;
|
||||
glBlendEquationEXT(GL_MAX_EXT);
|
||||
glRectf(x1, i, x2, i+deltaY);
|
||||
|
||||
i -= deltaY;
|
||||
glBlendEquationEXT(GL_FUNC_SUBTRACT_EXT);
|
||||
glRectf(x1, i, x2, i+deltaY);
|
||||
|
||||
i -= deltaY;
|
||||
glBlendEquationEXT(GL_FUNC_REVERSE_SUBTRACT_EXT);
|
||||
glRectf(x1, i, x2, i+deltaY);
|
||||
|
||||
glBlendFunc(GL_ONE, GL_ZERO);
|
||||
i -= deltaY;
|
||||
glBlendEquationEXT(GL_LOGIC_OP);
|
||||
glLogicOp(GL_CLEAR);
|
||||
glRectf(x1, i, x2, i+deltaY);
|
||||
|
||||
i -= deltaY;
|
||||
glBlendEquationEXT(GL_LOGIC_OP);
|
||||
glLogicOp(GL_SET);
|
||||
glRectf(x1, i, x2, i+deltaY);
|
||||
|
||||
i -= deltaY;
|
||||
glBlendEquationEXT(GL_LOGIC_OP);
|
||||
glLogicOp(GL_COPY);
|
||||
glRectf(x1, i, x2, i+deltaY);
|
||||
|
||||
i -= deltaY;
|
||||
glBlendEquationEXT(GL_LOGIC_OP);
|
||||
glLogicOp(GL_NOOP);
|
||||
glRectf(x1, i, x2, i+deltaY);
|
||||
|
||||
i -= deltaY;
|
||||
glBlendEquationEXT(GL_LOGIC_OP);
|
||||
glLogicOp(GL_AND);
|
||||
glRectf(x1, i, x2, i+deltaY);
|
||||
|
||||
i -= deltaY;
|
||||
glBlendEquationEXT(GL_LOGIC_OP);
|
||||
glLogicOp(GL_INVERT);
|
||||
glRectf(x1, i, x2, i+deltaY);
|
||||
|
||||
i -= deltaY;
|
||||
glBlendEquationEXT(GL_LOGIC_OP);
|
||||
glLogicOp(GL_OR);
|
||||
glRectf(x1, i, x2, i+deltaY);
|
||||
|
||||
i -= deltaY;
|
||||
glBlendEquationEXT(GL_LOGIC_OP);
|
||||
glLogicOp(GL_XOR);
|
||||
glRectf(x1, i, x2, i+deltaY);
|
||||
glRectf(x1, i+10, x2, i+5);
|
||||
|
||||
if (doPrint) {
|
||||
glDisable(GL_BLEND);
|
||||
glColor3f(1.0, 1.0, 1.0);
|
||||
PrintColorStrings();
|
||||
}
|
||||
glFlush();
|
||||
|
||||
if (doubleBuffer) {
|
||||
glutSwapBuffers();
|
||||
}
|
||||
|
||||
}
|
||||
|
||||
static GLenum Args(int argc, char **argv)
|
||||
{
|
||||
GLint i;
|
||||
|
||||
doubleBuffer = GL_FALSE;
|
||||
|
||||
for (i = 1; i < argc; i++) {
|
||||
if (strcmp(argv[i], "-sb") == 0) {
|
||||
doubleBuffer = GL_FALSE;
|
||||
} else if (strcmp(argv[i], "-db") == 0) {
|
||||
doubleBuffer = GL_TRUE;
|
||||
} else {
|
||||
printf("%s (Bad option).\n", argv[i]);
|
||||
return GL_FALSE;
|
||||
}
|
||||
}
|
||||
return GL_TRUE;
|
||||
}
|
||||
|
||||
int main(int argc, char **argv)
|
||||
{
|
||||
GLenum type;
|
||||
char *s;
|
||||
char *extName1 = "GL_EXT_blend_logic_op";
|
||||
char *extName2 = "GL_EXT_blend_minmax";
|
||||
char *extName3 = "GL_EXT_blend_subtract";
|
||||
|
||||
glutInit(&argc, argv);
|
||||
|
||||
if (Args(argc, argv) == GL_FALSE) {
|
||||
exit(1);
|
||||
}
|
||||
|
||||
glutInitWindowPosition(0, 0); glutInitWindowSize( 800, 400);
|
||||
|
||||
type = GLUT_RGB;
|
||||
type |= (doubleBuffer) ? GLUT_DOUBLE : GLUT_SINGLE;
|
||||
glutInitDisplayMode(type);
|
||||
|
||||
if (glutCreateWindow("Blend Equation") == GL_FALSE) {
|
||||
exit(1);
|
||||
}
|
||||
|
||||
/* Make sure blend_logic_op extension is there. */
|
||||
s = (char *) glGetString(GL_EXTENSIONS);
|
||||
if (!s)
|
||||
exit(1);
|
||||
if (strstr(s,extName1) == 0) {
|
||||
printf("Blend_logic_op extension is not present.\n");
|
||||
exit(1);
|
||||
}
|
||||
if (strstr(s,extName2) == 0) {
|
||||
printf("Blend_minmax extension is not present.\n");
|
||||
exit(1);
|
||||
}
|
||||
if (strstr(s,extName3) == 0) {
|
||||
printf("Blend_subtract extension is not present.\n");
|
||||
exit(1);
|
||||
}
|
||||
|
||||
Init();
|
||||
|
||||
glutReshapeFunc(Reshape);
|
||||
glutKeyboardFunc(Key);
|
||||
glutDisplayFunc(Draw);
|
||||
glutMainLoop();
|
||||
return 0;
|
||||
}
|
||||
Reference in New Issue
Block a user