Add color overwriting/clear for chr sprites

5 files changed, 50 insertions, 44 deletions

diff --git a/src/main.c b/src/main.c
index f531481..fa2384f 100644
--- a/src/main.c
+++ b/src/main.c
@@ -50,7 +50,7 @@ test_chr(void) {
 
     for (size_t y = 10; y < 20; y++) {
         for (size_t x = 20; x < 30; x++) {
-            draw_chr(8 + x * 8, 2 + y * 8, tile, 0, 0);
+            draw_chr(8 + x * 8, 2 + y * 8, tile, 0, 0, 0);
         }
     }
 }
@@ -234,14 +234,14 @@ test_sprites_bounce(void) {
         int flip_y;
     } Sprite;
     Sprite sprites[] = {
-        {50, 50, 1, 1, 1, 0, 0},
-        {20, 30, 2, 3, 2, 0, 1},
-        {10, 100, -2, -1, 3, 1, 0},
-        {200, 80, 1, -2, 4, 1, 1},
-        {50, 50, 1, 1, 1, 0, 0},
-        {20, 30, 2, 3, 2, 0, 1},
-        {10, 100, -2, -1, 3, 1, 0},
-        {200, 80, 1, -2, 4, 1, 1},
+        {50  , 50  , 1  , 1  , 0  , 0 , 0},
+        {20  , 30  , 2  , 3  , 1  , 0 , 1},
+        {10  , 100 , -2 , -1 , 2  , 1 , 0},
+        {200 , 75  , 1  , -2 , 3  , 1 , 1},
+        {55  , 45  , -1 , 1  , 4  , 0 , 0},
+        {25  , 35  , 2  , -3 , 5  , 0 , 1},
+        {15  , 95  , -2 , 1  , 6  , 1 , 0},
+        {210 , 75  , 1  , 2  , 15 , 1 , 1},
     };
     int should_move = 1;
     while (true) {
@@ -268,6 +268,7 @@ test_sprites_bounce(void) {
             PROF(draw_chr(
                     (240 - s->x - 8), (160 - s->y - 8),
                     sprite_chr,
+                    s->clr,
                     s->flip_x, s->flip_y), chr_cycles);
             s->x += s->inc_x * should_move;
             s->y += s->inc_y * should_move;
@@ -303,12 +304,12 @@ test_text_rendering(void) {
         PROF(flip_buffer(), flip_cycles);
         PROF(screen_fill(0), clear_cycles);
         txt_color(2);
-        txt_position(0, 8);
-        PROF(txt_drawf("The strongest bulwark of", 4, 0, 3), txt_drawf_cycles);
-        PROF(txt_drawf("authority is uniformity;", 2, 8, 3), txt_drawf_cycles);
-        PROF(txt_drawf("the least divergence from it", 8, 16, 3), txt_drawf_cycles);
-        PROF(txt_drawf("it's the greatest crime", 6, 24, 3), txt_drawf_cycles);
-        PROF(txt_drawf("- Emma Goldman", 100, 36, 3), txt_drawf_cycles);
+        PROF(txt_drawf("The strongest bulwark of", 4, 8 * 2, 3), txt_drawf_cycles);
+        PROF(txt_drawf("authority is uniformity;", 2, 8 * 3, 3), txt_drawf_cycles);
+        PROF(txt_drawf("the least divergence from it", 8, 8 * 4, 3), txt_drawf_cycles);
+        PROF(txt_drawf("it's the greatest crime", 6, 8 * 5, 3), txt_drawf_cycles);
+        PROF(txt_drawf("- Emma Goldman", 100, 8 * 6 + 3, 3), txt_drawf_cycles);
+        txt_position(0, 10);
         PROF(txt_printf("The only way to deal with an\n"
                    "unfree world is to become\n"
                    "so absolutely free,\n"
@@ -333,9 +334,6 @@ int main(void) {
     irq_init();
     irs_set(IRQ_VBLANK, irs_stub);
 
-    // TODO: Test for text rendering.
-    // TODO: Add a clear mode for chr that inverts non zero values to become
-    // zero, thus clearing the sprite if it was in the same position.
     while (true) {
         test_text_rendering();
         test_growing_rects();
diff --git a/src/profiling.c b/src/profiling.c
index 1686ad9..a464372 100644
--- a/src/profiling.c
+++ b/src/profiling.c
@@ -18,7 +18,7 @@
 #define PROF(F,VAR) \
     do { \
         u32 __tmp_prof = profile_measure();\
-        (F);\
+        F;\
         (VAR) += profile_measure() - __tmp_prof;\
     } while (0)
 
diff --git a/src/renderer.h b/src/renderer.h
index cf490d3..e6637ef 100644
--- a/src/renderer.h
+++ b/src/renderer.h
@@ -20,8 +20,10 @@ void draw_filled_rect(size_t x0, size_t y0, size_t x1, size_t y1, u8 clr);
 void screen_fill(u8 clr);
 
 // Draws a chr sprite (16 * u8). The first 8 bytes correspond to ch0 and the
-// last 8 to ch1.
-void draw_chr(size_t x, size_t y, u8 *sprite, u8 flip_x, u8 flip_y);
+// last 8 to ch1. If clr is 0 the regular 4bit color will be used, from clr 1-14
+// the given color will overwrite the existing one. Color 15 will "clear" the
+// sprite instead.
+void draw_chr(size_t x, size_t y, u8 *sprite, u8 clr, u8 flip_x, u8 flip_y);
 
 // Draws a 1bpp icn sprite in the given color.
 void draw_icn(size_t x, size_t y, u8 *sprite, u8 clr, u8 flip_x, u8 flip_y);
diff --git a/src/renderer_m0.c b/src/renderer_m0.c
index 7e598c3..10bbff5 100644
--- a/src/renderer_m0.c
+++ b/src/renderer_m0.c
@@ -460,7 +460,7 @@ decode_1bpp(u8 row, u8 flip_x) {
 IWRAM_CODE
 static inline
 void
-draw_2bpp_row(size_t x, size_t y, u8 a, u8 b, u8 flip_x) {
+draw_2bpp_row(size_t x, size_t y, u8 a, u8 b, u8 clr, u8 flip_x) {
     BOUNDCHECK_SCREEN(x, y);
 
     size_t tile_x = x / 8;
@@ -482,11 +482,16 @@ draw_2bpp_row(size_t x, size_t y, u8 a, u8 b, u8 flip_x) {
     u32 mask_a = (clr_a * 0xF);
     u32 mask_b = (clr_b * 0xF);
     u32 mask = (mask_a | mask_b);
-    u32 color = clr_a + (clr_b << 1);
+    u32 color;
+    if (clr == 0) {
+        color = clr_a + (clr_b << 1);
+    } else if (clr == 15) {
+        color = 0;
+    } else {
+        color = (clr_a | clr_b) * clr;
+    }
     dst[0] = (dst[0] & ~(mask << shift_left))  | (color << shift_left);
     dst[8] = (dst[8] & ~(mask >> shift_right)) | (color >> shift_right);
-
-    // TODO: different blend modes?
 }
 
 IWRAM_CODE
@@ -508,27 +513,25 @@ draw_1bpp_row(size_t x, size_t y, u8 a, u8 clr, u8 flip_x) {
     color *= clr;
     dst[0] = (dst[0] & ~(mask << shift_left))  | (color << shift_left);
     dst[8] = (dst[8] & ~(mask >> shift_right)) | (color >> shift_right);
-
-    // TODO: different blend modes?
 }
 
 IWRAM_CODE
 void
-draw_chr(size_t x, size_t y, u8 *sprite, u8 flip_x, u8 flip_y) {
+draw_chr(size_t x, size_t y, u8 *sprite, u8 clr, u8 flip_x, u8 flip_y) {
     BOUNDCHECK_SCREEN(x, y);
     if (!flip_y) {
         for(size_t v = 0; v < 8; v++) {
             if ((y + v) >= SCREEN_HEIGHT) break;
             u8 ch1 = sprite[v + 0];
             u8 ch2 = sprite[v + 8];
-            draw_2bpp_row(x, y + v, ch1, ch2, flip_x);
+            draw_2bpp_row(x, y + v, ch1, ch2, clr, flip_x);
         }
     } else {
         for(size_t v = 0; v < 8; v++) {
             if ((y + v) >= SCREEN_HEIGHT) break;
             u8 ch1 = sprite[(7 - v) + 0];
             u8 ch2 = sprite[(7 - v) + 8];
-            draw_2bpp_row(x, y + v, ch1, ch2, flip_x);
+            draw_2bpp_row(x, y + v, ch1, ch2, clr, flip_x);
         }
     }
 }
diff --git a/src/renderer_m4.c b/src/renderer_m4.c
index 73b51d5..657bb73 100644
--- a/src/renderer_m4.c
+++ b/src/renderer_m4.c
@@ -45,9 +45,9 @@ draw_pixel(size_t x, size_t y, u8 clr) {
     BOUNDCHECK_SCREEN(x, y);
     u16 *dst = &backbuf[(x + y * SCREEN_WIDTH) / 2];
     if(x & 1) {
-        *dst = (*dst &  0xFF) | (clr << 8);
+        *dst = (*dst &  0xF) | (clr << 8);
     } else {
-        *dst = (*dst & ~0xFF) | clr;
+        *dst = (*dst & ~0xF) | clr;
     }
 }
 
@@ -100,13 +100,13 @@ draw_vline(size_t x0, size_t y0, size_t y1, u8 clr) {
     size_t tile_x0 = x0 / 8;
     size_t start_col = x0 % 8;
     u16 *dst = &backbuf[(start_col + tile_x0 * 8 + y0 * SCREEN_WIDTH) / 2];
-    if(start_col & 1) {
+    if(x0 & 1) {
         for (size_t i = 0; i <= y1 - y0; i++, dst += SCREEN_WIDTH / 2) {
-            *dst = (*dst &  0xFF) | (clr << 8);
+            *dst = (*dst &  0xF) | (clr << 8);
         }
     } else {
         for (size_t i = 0; i <= y1 - y0; i++, dst += SCREEN_WIDTH / 2) {
-            *dst = (*dst & ~0xFF) | clr;
+            *dst = (*dst & ~0xF) | clr;
         }
     }
 }
@@ -439,7 +439,7 @@ decode_1bpp(u8 row, u8 flip_x) {
 IWRAM_CODE
 static inline
 void
-draw_2bpp_row(size_t x, size_t y, u8 a, u8 b, u8 flip_x) {
+draw_2bpp_row(size_t x, size_t y, u8 a, u8 b, u8 clr, u8 flip_x) {
     BOUNDCHECK_SCREEN(x, y);
 
     size_t tile_x = x / 8;
@@ -459,11 +459,16 @@ draw_2bpp_row(size_t x, size_t y, u8 a, u8 b, u8 flip_x) {
     u64 mask_a = (clr_a * 0xF);
     u64 mask_b = (clr_b * 0xF);
     u64 mask = (mask_a | mask_b);
-    u64 color = clr_a + (clr_b << 1);
+    u64 color;
+    if (clr == 0) {
+        color = clr_a + (clr_b << 1);
+    } else if (clr == 15) {
+        color = 0;
+    } else {
+        color = (clr_a | clr_b) * clr;
+    }
     dst[0] = (dst[0] & ~(mask << shift_left))  | (color << shift_left);
     dst[1] = (dst[1] & ~(mask >> shift_right)) | (color >> shift_right);
-
-    // TODO: different blend modes?
 }
 
 IWRAM_CODE
@@ -483,27 +488,25 @@ draw_1bpp_row(size_t x, size_t y, u8 a, u8 clr, u8 flip_x) {
     color *= clr;
     dst[0] = (dst[0] & ~(mask << shift_left))  | (color << shift_left);
     dst[1] = (dst[1] & ~(mask >> shift_right)) | (color >> shift_right);
-
-    // TODO: different blend modes?
 }
 
 IWRAM_CODE
 void
-draw_chr(size_t x, size_t y, u8 *sprite, u8 flip_x, u8 flip_y) {
+draw_chr(size_t x, size_t y, u8 *sprite, u8 clr, u8 flip_x, u8 flip_y) {
     BOUNDCHECK_SCREEN(x, y);
     if (!flip_y) {
         for(size_t v = 0; v < 8; v++) {
             if ((y + v) >= SCREEN_HEIGHT) break;
             u8 ch1 = sprite[v + 0];
             u8 ch2 = sprite[v + 8];
-            draw_2bpp_row(x, y + v, ch1, ch2, flip_x);
+            draw_2bpp_row(x, y + v, ch1, ch2, clr, flip_x);
         }
     } else {
         for(size_t v = 0; v < 8; v++) {
             if ((y + v) >= SCREEN_HEIGHT) break;
             u8 ch1 = sprite[(7 - v) + 0];
             u8 ch2 = sprite[(7 - v) + 8];
-            draw_2bpp_row(x, y + v, ch1, ch2, flip_x);
+            draw_2bpp_row(x, y + v, ch1, ch2, clr, flip_x);
         }
     }
 }