Refined toolchain instructions, organized examples, added automatic retry for CdRead(), added FIOCSCAN ioctl in psxsio TTY driver, added tty and console examples.

1 files changed, 108 insertions, 0 deletions

diff --git a/examples/graphics/fpscam/clip.c b/examples/graphics/fpscam/clip.c
new file mode 100644
index 0000000..7f2b780
--- /dev/null
+++ b/examples/graphics/fpscam/clip.c
@@ -0,0 +1,108 @@
+/* Polygon clip detection code
+ *
+ * The polygon clipping logic is based on the Cohen-Sutherland algorithm, but
+ * only the off-screen detection logic is used to determine which polygon edges
+ * are off-screen.
+ *
+ * In tri_clip, the following edges are checked as follows:
+ *
+ *  |\
+ *  |  \
+ *  |    \
+ *  |      \
+ *  |--------
+ *
+ * In quad_clip, the following edges are checked as follows:
+ *
+ *  |---------|
+ *  | \     / |
+ *  |   \ /   |
+ *  |   / \   |
+ *  | /     \ |
+ *  |---------|
+ *
+ * The inner portion of the quad is checked, otherwise the quad will be
+ * culled out if the camera faces right into it, where all four edges
+ * are off-screen at once.
+ *
+ */
+ 
+#include "clip.h"
+
+#define CLIP_LEFT	1
+#define CLIP_RIGHT	2
+#define CLIP_TOP	4
+#define CLIP_BOTTOM	8
+
+int test_clip(RECT *clip, short x, short y) {
+	
+	// Tests which corners of the screen a point lies outside of
+	
+	int result = 0;
+
+	if ( x < clip->x ) {
+		result |= CLIP_LEFT;
+	}
+	
+	if ( x >= (clip->x+(clip->w-1)) ) {
+		result |= CLIP_RIGHT;
+	}
+	
+	if ( y < clip->y ) {
+		result |= CLIP_TOP;
+	}
+	
+	if ( y >= (clip->y+(clip->h-1)) ) {
+		result |= CLIP_BOTTOM;
+	}
+
+	return result;
+	
+}
+
+int tri_clip(RECT *clip, DVECTOR *v0, DVECTOR *v1, DVECTOR *v2) {
+	
+	// Returns non-zero if a triangle is outside the screen boundaries
+	
+	short c[3];
+
+	c[0] = test_clip(clip, v0->vx, v0->vy);
+	c[1] = test_clip(clip, v1->vx, v1->vy);
+	c[2] = test_clip(clip, v2->vx, v2->vy);
+
+	if ( ( c[0] & c[1] ) == 0 )
+		return 0;
+	if ( ( c[1] & c[2] ) == 0 )
+		return 0;
+	if ( ( c[2] & c[0] ) == 0 )
+		return 0;
+
+	return 1;
+}
+
+int quad_clip(RECT *clip, DVECTOR *v0, DVECTOR *v1, DVECTOR *v2, DVECTOR *v3) {
+	
+	// Returns non-zero if a quad is outside the screen boundaries
+	
+	short c[4];
+
+	c[0] = test_clip(clip, v0->vx, v0->vy);
+	c[1] = test_clip(clip, v1->vx, v1->vy);
+	c[2] = test_clip(clip, v2->vx, v2->vy);
+	c[3] = test_clip(clip, v3->vx, v3->vy);
+
+	if ( ( c[0] & c[1] ) == 0 )
+		return 0;
+	if ( ( c[1] & c[2] ) == 0 )
+		return 0;
+	if ( ( c[2] & c[3] ) == 0 )
+		return 0;
+	if ( ( c[3] & c[0] ) == 0 )
+		return 0;
+	if ( ( c[0] & c[2] ) == 0 )
+		return 0;
+	if ( ( c[1] & c[3] ) == 0 )
+		return 0;
+
+	return 1;
+}
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