gpu/texture-flip rectangle test

Makefile

@@ -23,6 +23,7 @@ IMAGES = common \
 		gpu/mask-bit \
 		gpu/quad \
 		gpu/rectangles \
+		gpu/texture-flip \
 		gpu/texture-overflow \
 		gpu/transparency \
 		gpu/triangle \

README.md

@@ -46,6 +46,7 @@ lines                    | Draws lines using different modes - for verifying Bre
 mask-bit                 | Check Mask bit behavior during VRAM copy operations
 quad                     | Semi-transparent polygon commands - for testing fill rules and transparency handling
 rectangles               | Draws all combinations of Rectangle commands
+texture-flip             | Check gp0_e1.13 and gp0_e1.12 texture flip behaviour
 texture-overflow         | Draws textured rectangle with UV overflowing VRAM width
 transparency             | Draws rectangles with 4 semi-transparent blending modes
 triangle                 | Draws Gouroud shaded equilateral triangle 

gpu/texture-flip/Makefile

@@ -0,0 +1,3 @@
+TARGET = texture-flip.elf
+
+include ../../common-test.mk

gpu/texture-flip/main.c

@@ -0,0 +1,128 @@
+#include <common.h>
+
+#define SCR_W 320
+#define SCR_H 240
+
+const int texPageX = 640;
+const int texPageY = 0;
+
+uint16_t lastTpage = 0;
+void setTextureFlip(bool flipY, bool flipX) {
+    DR_TPAGE e;
+    setDrawTPage(&e, /* Drawing to display area */ 1, /* dithering */ 0, getTPage(/* bits = 15bit */ 2, /* transparencyMode */0, texPageX, texPageY));
+    e.code[0] |= (flipX << 12);
+    e.code[0] |= (flipY << 13);
+    lastTpage = e.code[0];
+    DrawPrim(&e);
+}
+
+void drawRectangle(int x, int y, int w, int h) {
+    SPRT s;
+    setSprt(&s);
+    setSemiTrans(&s, 0);
+    setRGB0(&s, 128, 128, 128 );
+    s.x0 = x;
+    s.y0 = y;
+    s.w = w;
+    s.h = h;
+    s.u0 = 0;
+    s.v0 = 0;
+    DrawPrim(&s);
+}
+
+void drawQuad(int x, int y, int w, int h) {
+    POLY_FT4 p;
+    setPolyFT4(&p);
+    setSemiTrans(&p, 0);
+    setRGB0(&p, 128, 128, 128 );
+    setClut(&p, 0, 0); // Not used
+    p.tpage = lastTpage;
+
+    p.x0 = x;   p.y0 = y;
+    p.x1 = x+w; p.y1 = y;
+    p.x2 = x;   p.y2 = y+h;
+    p.x3 = x+w; p.y3 = y+h;
+
+    p.u0 = 0;   p.v0 = 0;
+    p.u1 = w;   p.v1 = 0;
+    p.u2 = 0;   p.v2 = h;
+    p.u3 = w;   p.v3 = h;
+    DrawPrim(&p);
+}
+
+int main() {
+    initVideo(SCR_W, SCR_H);
+    printf("\ngpu/texture-flip\n");
+    printf("VRAM contents:\n"
+"0,0                                                       \n"
+"┌--------------------------------------------------------┐\n"
+"|┌--------┐ ┌--------┐     ┌---------┐                   |\n"
+"||        | |        |     |         |                   |\n"
+"|| Rect   | | Rect   |     | texture |                   |\n"
+"|| normal | | x-flip |     |         |                   |\n"
+"||        | |        |     |         |                   |\n"
+"||        | |        |     |         |                   |\n"
+"│└--------┘ └--------┘     └---------┘                   |\n"
+"|                                                        |\n"
+"│┌--------┐ ┌--------┐     ┌--┐  ┌--┐                    |\n"
+"||        | |        |     | r|  | r|  64x64rect         |\n"
+"|| Rect   | | Rect   |     └--┘  └--┘  2nd flipped       |\n"
+"|| y-flip | | x&y    |                                   |\n"
+"||        | | flip   |     ┌--┐  ┌--┐  64x64 quad        |\n"
+"||        | |        |     | q|  | q|  2nd flipped       |\n"
+"|└--------┘ └--------┘     └--┘  └--┘(should be the same)|\n"
+"└--------------------------------------------------------┘\n"
+"                                                1023, 1023\n\n");
+
+    clearScreenColor(0xff, 0xff, 0xff);
+
+    const int W = 256;
+    const int H = 256;
+    // Make texture
+    for (int i = 0; i < 0xffff; i++) {
+        int x = texPageX + i % W; 
+        int y = texPageY + i / W;
+        vramPut(x, y, i);
+    }
+
+    // 0x0 - normal
+    setTextureFlip(0, 0);
+    drawRectangle(0, 0, W, H);
+
+    // 260x0 - x flipped
+    setTextureFlip(0, 1);
+    drawRectangle(260, 0, W, H);
+
+    // 260x0 - y flipped
+    setTextureFlip(1, 0);
+    drawRectangle(0, 260, W, H);
+
+    // 260x260 - x&&y flipped
+    setTextureFlip(1, 1);
+    drawRectangle(260, 260, W, H);
+
+
+    // 640x260 - normal (small rect)
+    setTextureFlip(0, 0);
+    drawRectangle(640, 260, 64, 64);
+
+    // 640x260 - x&&y flipped (small rect)
+    setTextureFlip(1, 1);
+    drawRectangle(714, 260, 64, 64);
+
+
+    // Check polygons as well, just to be sure
+    // 640x260 - normal (small polygon)
+    setTextureFlip(0, 0);
+    drawQuad(640, 334, 64, 64);
+
+    // 640x260 - x&&y flipped (small polygon)
+    setTextureFlip(1, 1);
+    drawQuad(714, 334, 64, 64);
+
+    printf("Done.\n");
+    for (;;) {
+        VSync(0);
+    }
+    return 0;
+}