From c1225cfbbc2614bbca205b84fdc9978354729935 Mon Sep 17 00:00:00 2001
From: Miloslav Ciz <drummyfish@dissroot.org>
Date: Sat, 16 Apr 2022 22:58:49 +0200
Subject: [PATCH] Optimize examples

---
 programs/city.c        | 27 ++++++++++++---------------
 programs/level.c       | 30 +++++++++++++++---------------
 programs/modelViewer.c | 34 ++++++++++++++--------------------
 3 files changed, 41 insertions(+), 50 deletions(-)

diff --git a/programs/city.c b/programs/city.c
index 448e607..6c3919d 100644
--- a/programs/city.c
+++ b/programs/city.c
@@ -81,16 +81,13 @@ void clearScreen()
 
 static inline void setPixel(int x, int y, uint8_t red, uint8_t green, uint8_t blue)
 {
-  uint32_t r = red & 0x000000FF;
-  r = r << 24;
+  uint8_t *p = ((uint8_t *) pixels) + (y * S3L_RESOLUTION_X + x) * 4 + 1;
 
-  uint32_t g = green & 0x000000FF;
-  g = g << 16;
-
-  uint32_t b = blue & 0x000000FF;
-  b = b << 8;
-
-  pixels[y * S3L_RESOLUTION_X + x] = r | g | b;
+  *p = blue;
+  ++p;
+  *p = green;
+  ++p;
+  *p = red;
 }
 
 void sampleTexture(int32_t u, int32_t v, uint8_t *r, uint8_t *g, uint8_t *b)
@@ -98,13 +95,13 @@ void sampleTexture(int32_t u, int32_t v, uint8_t *r, uint8_t *g, uint8_t *b)
   u = S3L_clamp(u,0,CITY_TEXTURE_WIDTH - 1);
   v = S3L_clamp(v,0,CITY_TEXTURE_HEIGHT - 1);
 
-  int32_t index = (v * CITY_TEXTURE_WIDTH + u) * 3;
+  const uint8_t *t = cityTexture + (v * CITY_TEXTURE_WIDTH + u) * 3;
 
-  *r = cityTexture[index];
-  index++;
-  *g = cityTexture[index];
-  index++;
-  *b = cityTexture[index];
+  *r = *t;
+  t++;
+  *g = *t;
+  t++;
+  *b = *t;
 }
 
 uint32_t previousTriangle = -1;
diff --git a/programs/level.c b/programs/level.c
index 4dcd35d..fa978a3 100644
--- a/programs/level.c
+++ b/programs/level.c
@@ -6,6 +6,7 @@
 */
 
 #define TEXTURES 1 // whether to use textures for the level
+#define FOG 1
 
 #include <SDL2/SDL.h>
 #include <stdio.h>
@@ -53,16 +54,13 @@ void clearScreen()
 
 static inline void setPixel(int x, int y, uint8_t red, uint8_t green, uint8_t blue)
 {
-  uint32_t r = red & 0x000000FF;
-  r = r << 24;
+  uint8_t *p = ((uint8_t *) pixels) + (y * S3L_resolutionX + x) * 4 + 1;
 
-  uint32_t g = green & 0x000000FF;
-  g = g << 16;
-
-  uint32_t b = blue & 0x000000FF;
-  b = b << 8;
-
-  pixels[y * S3L_resolutionX + x] = r | g | b;
+  *p = blue;
+  ++p;
+  *p = green;
+  ++p;
+  *p = red;
 }
 
 void sampleTexture(S3L_Unit u, S3L_Unit v, uint8_t *r, uint8_t *g, uint8_t *b)
@@ -73,13 +71,13 @@ void sampleTexture(S3L_Unit u, S3L_Unit v, uint8_t *r, uint8_t *g, uint8_t *b)
   u = S3L_wrap(u,LEVEL_TEXTURE_WIDTH);
   v = S3L_wrap(v,LEVEL_TEXTURE_HEIGHT);
 
-  uint32_t index = (v * LEVEL_TEXTURE_WIDTH + u) * 3;
+  const uint8_t *t = texture + (v * LEVEL_TEXTURE_WIDTH + u) * 3;
 
-  *r = texture[index];
-  index++;
-  *g = texture[index];
-  index++;
-  *b = texture[index];
+  *r = *t;
+  t++;
+  *g = *t;
+  t++;
+  *b = *t;
 }
 
 void drawTeleport(int16_t x, int16_t y, S3L_ScreenCoord size)
@@ -161,6 +159,7 @@ void drawPixel(S3L_PixelInfo *p)
   }
 #endif
 
+#if FOG
   S3L_Unit fog = (p->depth * 
 #if TEXTURES
     8
@@ -172,6 +171,7 @@ void drawPixel(S3L_PixelInfo *p)
   r = S3L_clamp(((S3L_Unit) r) - fog,0,255);
   g = S3L_clamp(((S3L_Unit) g) - fog,0,255);
   b = S3L_clamp(((S3L_Unit) b) - fog,0,255);
+#endif
 
   setPixel(p->x,p->y,r,g,b); 
 }
diff --git a/programs/modelViewer.c b/programs/modelViewer.c
index 8529ee9..8a9a1b5 100644
--- a/programs/modelViewer.c
+++ b/programs/modelViewer.c
@@ -98,19 +98,13 @@ void clearScreen()
 
 static inline void setPixel(int x, int y, uint8_t red, uint8_t green, uint8_t blue)
 {
-  if (x < 0 || x >= S3L_RESOLUTION_X || y < 0 || y >= S3L_RESOLUTION_Y)
-    return;
+  uint8_t *p = ((uint8_t *) pixels) + (y * S3L_RESOLUTION_X + x) * 4 + 1;
 
-  uint32_t r = red & 0x000000FF;
-  r = r << 24;
-
-  uint32_t g = green & 0x000000FF;
-  g = g << 16;
-
-  uint32_t b = blue & 0x000000FF;
-  b = b << 8;
-
-  pixels[y * S3L_RESOLUTION_X + x] = r | g | b;
+  *p = blue;
+  ++p;
+  *p = green;
+  ++p;
+  *p = red;
 }
 
 void sampleTexture(int32_t u, int32_t v, uint8_t *r, uint8_t *g, uint8_t *b)
@@ -118,13 +112,13 @@ void sampleTexture(int32_t u, int32_t v, uint8_t *r, uint8_t *g, uint8_t *b)
   u = S3L_clamp(u,0,TEXTURE_W - 1);
   v = S3L_clamp(v,0,TEXTURE_H - 1);
 
-  int32_t index = (v * TEXTURE_W + u) * 3;
+  const uint8_t *t = texture + (v * TEXTURE_W + u) * 3;
 
-  *r = texture[index];
-  index++;
-  *g = texture[index];
-  index++;
-  *b = texture[index];
+  *r = *t;
+  t++;
+  *g = *t;
+  t++;
+  *b = *t;
 }
 
 void animate(double time)
@@ -310,7 +304,7 @@ void drawPixel(S3L_PixelInfo *p)
     setPixel(p->x,p->y,r,g,b); 
 }
 
-void draw()
+void draw(void)
 {
   S3L_newFrame();
   clearScreen();
@@ -366,7 +360,7 @@ void setModel(uint8_t index)
 
 int16_t fps = 0;
 
-int main()
+int main(void)
 {
   printHelp();