From 370eca12ad8b40bfc32c206a526d53f4c777156d Mon Sep 17 00:00:00 2001 From: Brian Date: Thu, 28 Feb 2008 17:42:18 -0700 Subject: Added calibrate_rast.c program Measures rasterization of points/lines/tris and suggests fixes/biases when something doesn't meet spec. --- progs/tests/Makefile | 1 + progs/tests/calibrate_rast.c | 395 +++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 396 insertions(+) create mode 100644 progs/tests/calibrate_rast.c diff --git a/progs/tests/Makefile b/progs/tests/Makefile index 8196c1b348..7053ebc86a 100644 --- a/progs/tests/Makefile +++ b/progs/tests/Makefile @@ -30,6 +30,7 @@ SOURCES = \ bug_3050.c \ bug_3101.c \ bug_3195.c \ + calibrate_rast.c \ copypixrate.c \ crossbar.c \ cva.c \ diff --git a/progs/tests/calibrate_rast.c b/progs/tests/calibrate_rast.c new file mode 100644 index 0000000000..37d8ac85e5 --- /dev/null +++ b/progs/tests/calibrate_rast.c @@ -0,0 +1,395 @@ +/* + * Automatic primitive rasterization precision test. + * + * Draw prims at various sub-pixel offsets and examine where the quad is + * actually drawn. + * Check if the range of offsets which paint the right pixels falls within + * OpenGL's specification. + * In case of failures, report the coordinate bias needed to fix the problem. + * + * Note that even Mesa/swrast fails some line tests. This is because some + * window coordinates wind up as 53.9999 instead of 54, for example. Enabling + * the small translation factor below fixes that. Revisit someday... + * + * Brian Paul + * 28 Feb 2008 + */ + + +#include +#include +#include +#include + + +static int Width = 100, Height = 100; +static int Win; +static float Step = 0.125; +#if 0 +/* This tiny offset fixes errors in Mesa/Xlib */ +static float Xtrans = 0.5 * 0.125; +static float Ytrans = 0.5 * 0.125; +#else +static float Xtrans = 0.0; +static float Ytrans = 0.0; +#endif + + +static void +PointCalibrate(int xpos, int ypos) +{ + GLfloat rgba[4]; + float x, y; + float xmin, ymin, xmax, ymax; + + xmin = ymin = 1000.0; + xmax = ymax = -1000.0; + + for (y = -1.0; y <= 1.0; y += Step) { + for (x = -1.0; x <= 1.0; x += Step) { + glClear(GL_COLOR_BUFFER_BIT); + glBegin(GL_POINTS); + glVertex2f(xpos + x, ypos + y); + glEnd(); + glReadPixels(xpos, ypos, 1, 1, GL_RGBA, GL_FLOAT, rgba); + if (rgba[0] == 1.0 && rgba[1] == 1.0 && rgba[2] == 1.0) { + /* hit */ + if (x < xmin) + xmin = x; + if (y < ymin) + ymin = y; + if (x > xmax) + xmax = x; + if (y > ymax) + ymax = y; + } + } + } + + printf("Point at (%2d, %2d) drawn for x in [%6.3f, %6.3f] and y in [%6.3f, %6.3f]\n", + xpos, ypos, + xpos + xmin, xpos + xmax, + ypos + ymin, ypos + ymax); + + if (xmax - xmin != 1.0 - Step) { + printf(" => Inconsistant X-axis rasterization!\n"); + } + if (ymax - ymin != 1.0 - Step) { + printf(" => Inconsistant Y-axis rasterization!\n"); + } + if (xmin < 0.0) { + printf(" => Points should be X biased by about %f\n", xmin); + } + if (ymin < 0.0) { + printf(" => Points should be Y biased by about %f\n", ymin); + } + if (xmax > 1.0) { + printf(" => Points should be X biased by about %f\n", 1.0 - xmax); + } + if (ymax > 1.0) { + printf(" => Points should be Y biased by about %f\n", 1.0 - ymax); + } + +} + + +/** + * XXX Implement VLineCalibrate() someday + */ +static void +HLineCalibrate(int xpos, int ypos, int len) +{ + GLfloat rgba[2][4]; + float x, y; + float ymin, ymax; + float xmin_left, xmax_left, xmin_right, xmax_right; + + xmin_left = xmin_right = 1000.0; + xmax_left = xmax_right = -1000.0; + ymin = 1000; + ymax = -1000.0; + + /* + * First, check vertical positioning of the horizontal line + */ + for (y = -1.0; y <= 1.0; y += Step) { + glClear(GL_COLOR_BUFFER_BIT); + glBegin(GL_LINES); + glVertex2f(xpos, ypos + y); + glVertex2f(xpos + len, ypos + y); + glEnd(); + + glReadPixels(xpos + len / 2, ypos, 1, 1, GL_RGBA, GL_FLOAT, rgba); + if (rgba[0][0] == 1.0) { + /* hit */ + if (y < ymin) + ymin = y; + if (y > ymax) + ymax = y; + } + } + + printf("H-line at Y=%2d drawn for y in [%6.3f, %6.3f]\n", + ypos, + ypos + ymin, ypos + ymax); + + if (ymax - ymin != 1.0 - Step) { + printf(" => Inconsistant Y-axis rasterization!\n"); + } + + if (ymin > 0.5 ) { + printf(" => Lines should be Y biased by about %f\n", ymin - 0.5); + } + + if (ymax < 0.5 ) { + printf(" => Lines should be Y biased by about %f\n", 0.5 - ymax); + } + + /* + * Second, check endpoints (for Y at 1/2 pixel) + */ + for (x = -1.0; x <= 1.0; x += Step) { + glClear(GL_COLOR_BUFFER_BIT); + glBegin(GL_LINES); + glVertex2f(xpos + x, ypos + 0.5f); + glVertex2f(xpos + x + len, ypos + 0.5f); + glEnd(); + + /* left end */ + glReadPixels(xpos - 1, ypos, 2, 1, GL_RGBA, GL_FLOAT, rgba); + if (rgba[0][0] == 0.0 && rgba[1][0] == 1.0) { + /* hit */ + if (x < xmin_left) + xmin_left = x; + if (x > xmax_left) + xmax_left = x; + } + + /* right end */ + glReadPixels(xpos + len - 1, ypos, 2, 1, GL_RGBA, GL_FLOAT, rgba); + if (rgba[0][0] == 1.0 && rgba[1][0] == 0.0) { + /* hit */ + if (x < xmin_right) + xmin_right = x; + if (x > xmax_right) + xmax_right = x; + } + } + + printf("H-line [%d..%d) hit left end for x in [%6.3f, %6.3f] " + "hit right end for x in [%6.3f, %6.3f]\n", + xpos, xpos + len, + xpos + xmin_left, xpos + xmax_left, + xpos + len + xmin_right, xpos + len + xmax_right); + + if (xmax_left - xmin_left > 1.0 - Step) { + printf(" => Inconsistant left-end rasterization!\n"); + } + if (xmax_right - xmin_right > 1.0 - Step) { + printf(" => Inconsistant right-end rasterization!\n"); + } + + if (xmin_left != xmin_right || + xmax_left != xmax_right) { + printf(" => Inconsistant length!\n"); + } + + if (xmin_left < 0.0) { + printf(" => Coords should be X biased by about %f\n", xmin_left ); + } + if (xmin_right < 0.0) { + printf(" => Coords should be X biased by about %f\n", xmin_right ); + } + if (xmax_left >= 1.0) { + printf(" => Coords should be X biased by about %f\n", -xmax_right + 1.0); + } + if (xmax_right >= 1.0) { + printf(" => Coords should be X biased by about %f\n", -xmax_right + 1.0); + } + +} + + +static void +QuadCalibrate(int xpos, int ypos, int width, int height) +{ + GLfloat rgba1[2][4]; + GLfloat rgba2[2][4]; + float x, y; + float xmin, ymin, xmax, ymax; + + xmin = ymin = 1000.0; + xmax = ymax = -1000.0; + + for (y = -1.0; y <= 1.0; y += Step) { + for (x = -1.0; x <= 1.0; x += Step) { + glClear(GL_COLOR_BUFFER_BIT); + glBegin(GL_QUADS); + glVertex2f(xpos + x, ypos + y); + glVertex2f(xpos + x + width, ypos + y); + glVertex2f(xpos + x + width, ypos + y + height); + glVertex2f(xpos + x, ypos + y + height); + glEnd(); + + /* horizontal measurement */ + glReadPixels(xpos - 1, ypos + 2, 2, 1, GL_RGBA, GL_FLOAT, rgba1); + glReadPixels(xpos + width - 1, ypos + 2, 2, 1, GL_RGBA, GL_FLOAT, rgba2); + if (rgba1[0][0] == 0.0 && rgba1[1][0] == 1.0 && + rgba2[0][0] == 1.0 && rgba2[1][0] == 0.0) { + if (x < xmin) + xmin = x; + if (x > xmax) + xmax = x; + } + + /* vertical measurement */ + glReadPixels(xpos + 2, ypos - 1, 1, 2, GL_RGBA, GL_FLOAT, rgba1); + glReadPixels(xpos + 2, ypos + height - 1, 1, 2, GL_RGBA, GL_FLOAT, rgba2); + if (rgba1[0][0] == 0.0 && rgba1[1][0] == 1.0 && + rgba2[0][0] == 1.0 && rgba2[1][0] == 0.0) { + if (y < ymin) + ymin = y; + if (y > ymax) + ymax = y; + } + } + } + + printf("Quad at (%2d, %2d)..(%2d, %2d) drawn" + " for x in [%6.3f, %6.3f] and y in [%6.3f, %6.3f]\n", + xpos, ypos, + xpos + width, ypos + height, + xpos + xmin, xpos + xmax, + ypos + ymin, ypos + ymax); + + if (xmax - xmin != 1.0 - Step) { + printf(" => Inconsistant X-axis rasterization/size!\n"); + } + if (ymax - ymin != 1.0 - Step) { + printf(" => Inconsistant Y-axis rasterization/size!\n"); + } + + if (xmin < -0.5) { + printf(" => Coords should be X biased by about %f\n", 0.5 + xmin ); + } + if (ymin < -0.5) { + printf(" => Coords should be Y biased by about %f\n", 0.5 + ymin); + } + if (xmax > 0.5) { + printf(" => Coords should be X biased by about %f\n", -xmax + 0.5); + } + if (ymax > 0.5) { + printf(" => Coords should be Y biased by about %f\n", -ymax + 0.5); + } +} + + +/** + * Misc/disabled code for debugging. + */ +static void +DebugTest(void) +{ + glClear(GL_COLOR_BUFFER_BIT); + glEnable(GL_BLEND); + glBlendFunc(GL_ONE, GL_ONE); + + glColor3f(.5, .5, .5); + + glBegin(GL_LINES); + glVertex2f(30, 35.5); + glVertex2f(54, 35.5); + glVertex2f(54, 35.5); + glVertex2f(66, 35.5); + glEnd(); + + glDisable(GL_BLEND); + glColor3f(1,1,1); +} + + +static void +Draw(void) +{ + glClear(GL_COLOR_BUFFER_BIT); + + glPushMatrix(); + glTranslatef(Xtrans, Ytrans, 0); + + PointCalibrate(1, 1); + PointCalibrate(50, 50); + PointCalibrate(28, 17); + PointCalibrate(17, 18); + printf("\n"); + + HLineCalibrate(5, 10, 10); + HLineCalibrate(25, 22, 12); + HLineCalibrate(54, 33, 12); + HLineCalibrate(54+12, 33, 12); + printf("\n"); + + QuadCalibrate(2, 2, 10, 10); + QuadCalibrate(50, 50, 10, 10); + QuadCalibrate(28, 17, 12, 12); + QuadCalibrate(17, 28, 12, 12); + + (void) DebugTest; + + glPopMatrix(); + + glutSwapBuffers(); +} + + +static void +Reshape(int width, int height) +{ + Width = width; + Height = height; + glViewport(0, 0, width, height); + glMatrixMode(GL_PROJECTION); + glLoadIdentity(); + glOrtho(0, width, 0, height, -1, 1); + glMatrixMode(GL_MODELVIEW); + glLoadIdentity(); +} + + +static void +Key(unsigned char key, int x, int y) +{ + (void) x; + (void) y; + switch (key) { + case 27: + glutDestroyWindow(Win); + exit(0); + break; + } + glutPostRedisplay(); +} + + +static void +Init(void) +{ + printf("Measurement/callibration for basic prim rasterization...\n"); + printf("GL_RENDERER: %s\n", (char*) glGetString(GL_RENDERER)); +} + + +int +main(int argc, char *argv[]) +{ + glutInit(&argc, argv); + glutInitWindowPosition(0, 0); + glutInitWindowSize(Width, Height); + glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE); + Win = glutCreateWindow(argv[0]); + glutReshapeFunc(Reshape); + glutKeyboardFunc(Key); + glutDisplayFunc(Draw); + Init(); + glutMainLoop(); + return 0; +} -- cgit v1.2.3