[N-Gage] Micro-optimize rendering back-end

- Skip SDL_GetRenderScale call in Copy() fast path
- Cache last clear color to avoid redundant SetBrushColor calls
- Add whole-image bounds pre-check to skip per-pixel checks in rotation
- Simplify color packing in DrawPoints/FillRects to reduce overhead

src/render/ngage/SDL_render_ngage.cpp

@@ -174,7 +174,7 @@ CRenderer *CRenderer::NewL()
     return self;
 }
 
-CRenderer::CRenderer() : iRenderer(0), iDirectScreen(0), iScreenGc(0), iWsSession(), iWsWindowGroup(), iWsWindowGroupID(0), iWsWindow(), iWsScreen(0), iWsEventStatus(), iWsEvent(), iShowFPS(EFalse), iFPS(0), iFont(0), iWorkBuffer1(0), iWorkBuffer2(0), iWorkBufferSize(0), iTempRenderBitmap(0), iTempRenderBitmapWidth(0), iTempRenderBitmapHeight(0), iLastColorR(-1), iLastColorG(-1), iLastColorB(-1), iLinePointsBuffer(0), iLinePointsBufferCapacity(0), iLastDrawColor(0)
+CRenderer::CRenderer() : iRenderer(0), iDirectScreen(0), iScreenGc(0), iWsSession(), iWsWindowGroup(), iWsWindowGroupID(0), iWsWindow(), iWsScreen(0), iWsEventStatus(), iWsEvent(), iShowFPS(EFalse), iFPS(0), iFont(0), iWorkBuffer1(0), iWorkBuffer2(0), iWorkBufferSize(0), iTempRenderBitmap(0), iTempRenderBitmapWidth(0), iTempRenderBitmapHeight(0), iLastColorR(-1), iLastColorG(-1), iLastColorB(-1), iLinePointsBuffer(0), iLinePointsBufferCapacity(0), iLastDrawColor(0), iLastClearColor(0xFFFFFFFF)
 {
 }
 
@@ -313,7 +313,11 @@ void CRenderer::AbortNow(RDirectScreenAccess::TTerminationReasons aReason)
 void CRenderer::Clear(TUint32 iColor)
 {
     if (iRenderer && iRenderer->Gc()) {
+        // Skip redundant SetBrushColor if color hasn't changed.
+        if (iColor != iLastClearColor) {
             iRenderer->Gc()->SetBrushColor(iColor);
+            iLastClearColor = iColor;
+        }
         iRenderer->Gc()->Clear();
     }
 }
@@ -534,20 +538,24 @@ bool CRenderer::Copy(SDL_Renderer *renderer, SDL_Texture *texture, const SDL_Rec
 
     SDL_FColor *c = &texture->color;
 
-    // Get render scale once.
+    // Fast path 1: No transformations needed; direct BitBlt.
+    if (c->a == 1.f && c->r == 1.f && c->g == 1.f && c->b == 1.f) {
+        // Only check render scale if color mod passes.
         float sx;
         float sy;
         SDL_GetRenderScale(renderer, &sx, &sy);
-
+        if (sx == 1.f && sy == 1.f) {
-    // Fast path 1: No transformations needed; direct BitBlt.
-    if (c->a == 1.f && c->r == 1.f && c->g == 1.f && c->b == 1.f && sx == 1.f && sy == 1.f) {
             TRect aSource(TPoint(srcrect->x, srcrect->y), TSize(srcrect->w, srcrect->h));
             TPoint aDest(dstrect->x, dstrect->y);
             iRenderer->Gc()->BitBlt(aDest, phdata->bitmap, aSource);
             return true;
         }
+    }
 
     // Slow path: Transformations needed.
+    float sx;
+    float sy;
+    SDL_GetRenderScale(renderer, &sx, &sy);
     int w = phdata->cachedWidth;
     int h = phdata->cachedHeight;
     int pitch = phdata->cachedPitch;
@@ -617,13 +625,13 @@ bool CRenderer::CopyEx(SDL_Renderer *renderer, SDL_Texture *texture, const NGAGE
     SDL_FColor *c = &texture->color;
 
     // Pre-calculate common checks.
-    const bool isIdentityScale = (copydata->scale_x == Int2Fix(1) && copydata->scale_y == Int2Fix(1));
-    const bool isNoRotation = (copydata->angle == 0);
     const bool isNoFlip = (!copydata->flip);
+    const bool isNoRotation = (copydata->angle == 0);
     const bool isNoColorMod = (c->a == 1.f && c->r == 1.f && c->g == 1.f && c->b == 1.f);
+    const bool isIdentityScale = (copydata->scale_x == Int2Fix(1) && copydata->scale_y == Int2Fix(1));
 
     // Fast path 1: No transformations needed; direct BitBlt.
-    if (isNoFlip && isIdentityScale && isNoRotation && isNoColorMod) {
+    if (isNoFlip && isNoRotation && isNoColorMod && isIdentityScale) {
         TRect aSource(TPoint(copydata->srcrect.x, copydata->srcrect.y), TSize(copydata->srcrect.w, copydata->srcrect.h));
         TPoint aDest(copydata->dstrect.x, copydata->dstrect.y);
         iRenderer->Gc()->BitBlt(aDest, phdata->bitmap, aSource);
@@ -799,11 +807,8 @@ void CRenderer::DrawPoints(NGAGE_Vertex *aVerts, const TInt aCount)
         bool colorSet = false;
 
         for (TInt i = 0; i < aCount; i++, aVerts++) {
-            Uint8 ca = aVerts->color.a;
+            TUint32 aColor = (TUint32(aVerts->color.a) << 24) | (TUint32(aVerts->color.b) << 16) |
-            Uint8 cr = aVerts->color.r;
+                             (TUint32(aVerts->color.g) << 8) | TUint32(aVerts->color.r);
-            Uint8 cg = aVerts->color.g;
-            Uint8 cb = aVerts->color.b;
-            TUint32 aColor = (ca << 24) | (cb << 16) | (cg << 8) | cr;
 
             // Only set pen color when it changes.
             if (!colorSet || aColor != currentColor) {
@@ -830,11 +835,8 @@ void CRenderer::FillRects(NGAGE_Vertex *aVerts, const TInt aCount)
             TSize size(aVerts[i + 1].x, aVerts[i + 1].y);
             TRect rect(pos, size);
 
-            Uint8 ca = aVerts[i].color.a;
+            TUint32 aColor = (TUint32(aVerts[i].color.a) << 24) | (TUint32(aVerts[i].color.b) << 16) |
-            Uint8 cr = aVerts[i].color.r;
+                             (TUint32(aVerts[i].color.g) << 8) | TUint32(aVerts[i].color.r);
-            Uint8 cg = aVerts[i].color.g;
-            Uint8 cb = aVerts[i].color.b;
-            TUint32 aColor = (ca << 24) | (cb << 16) | (cg << 8) | cr;
 
             // Only set colors when they change.
             if (!colorSet || aColor != currentColor) {

src/render/ngage/SDL_render_ngage_c.hpp

@@ -111,6 +111,9 @@ class CRenderer : public MDirectScreenAccess
     // Cached draw color to avoid redundant SetPenColor/SetBrushColor calls.
     TUint32 iLastDrawColor;
 
+    // Cached clear color to avoid redundant SetBrushColor calls.
+    TUint32 iLastClearColor;
+
     // Helper methods.
     bool EnsureWorkBufferCapacity(TInt aRequiredSize);
     bool EnsureTempBitmapCapacity(TInt aWidth, TInt aHeight);

src/render/ngage/SDL_render_ops.cpp

@@ -98,6 +98,22 @@ void ApplyFlip(void *dest, void *source, int pitch, int width, int height, SDL_F
     const bool flipHorizontal = (flip & SDL_FLIP_HORIZONTAL) != 0;
     const bool flipVertical = (flip & SDL_FLIP_VERTICAL) != 0;
 
+    // Fast path: No flip; just copy entire buffer.
+    if (!flipHorizontal && !flipVertical) {
+        Mem::Copy(dest, source, pitch * height);
+        return;
+    }
+
+    // Fast path: Vertical-only flip; copy rows in reverse order.
+    if (flipVertical && !flipHorizontal) {
+        for (int y = 0; y < height; ++y) {
+            const int src_y = height - 1 - y;
+            Mem::Copy(&dst_pixels[y * pitchPixels], &src_pixels[src_y * pitchPixels], pitch);
+        }
+        return;
+    }
+
+    // Slow path: Horizontal or both flips; need pixel-level operations.
     // Pre-calculate width/height bounds for horizontal/vertical flipping.
     const int width_m1 = width - 1;
     const int height_m1 = height - 1;
@@ -150,6 +166,27 @@ void ApplyRotation(void *dest, void *source, int pitch, int width, int height, T
     // Pre-calculate pitch in pixels to avoid repeated division.
     const TInt pitchPixels = pitch >> 1;
 
+    // Pre-check if rotation keeps all pixels within bounds to skip per-pixel checks.
+    // Calculate the four corners of the image after rotation around center.
+    bool allInBounds = true;
+    if (angle != 0) {
+        // Check corners: (0,0), (width-1,0), (0,height-1), (width-1,height-1)
+        TFixed corners_x[4] = { -center_x, Int2Fix(width - 1) - center_x, -center_x, Int2Fix(width - 1) - center_x };
+        TFixed corners_y[4] = { -center_y, -center_y, Int2Fix(height - 1) - center_y, Int2Fix(height - 1) - center_y };
+
+        for (int i = 0; i < 4; ++i) {
+            TFixed rot_x = FixMul(corners_x[i], cos_angle) - FixMul(corners_y[i], sin_angle) + center_x;
+            TFixed rot_y = FixMul(corners_x[i], sin_angle) + FixMul(corners_y[i], cos_angle) + center_y;
+            int final_x = Fix2Int(rot_x);
+            int final_y = Fix2Int(rot_y);
+
+            if (final_x < 0 || final_x >= width || final_y < 0 || final_y >= height) {
+                allInBounds = false;
+                break;
+            }
+        }
+    }
+
     // Incremental DDA: Calculate per-pixel increments.
     // As we move right (x+1), the rotated position changes by (cos, -sin).
     const TFixed dx_cos = cos_angle;
@@ -172,7 +209,50 @@ void ApplyRotation(void *dest, void *source, int pitch, int width, int height, T
 
         int x = 0;
 
-        // Process 4 pixels at once.
+        if (allInBounds) {
+            // Fast path: No bounds checking needed.
+            for (; x < width - 3; x += 4) {
+                // Pixel 0
+                int final_x0 = Fix2Int(src_x);
+                int final_y0 = Fix2Int(src_y);
+                src_x += dx_cos;
+                src_y += dx_sin;
+
+                // Pixel 1
+                int final_x1 = Fix2Int(src_x);
+                int final_y1 = Fix2Int(src_y);
+                src_x += dx_cos;
+                src_y += dx_sin;
+
+                // Pixel 2
+                int final_x2 = Fix2Int(src_x);
+                int final_y2 = Fix2Int(src_y);
+                src_x += dx_cos;
+                src_y += dx_sin;
+
+                // Pixel 3
+                int final_x3 = Fix2Int(src_x);
+                int final_y3 = Fix2Int(src_y);
+                src_x += dx_cos;
+                src_y += dx_sin;
+
+                // Write all 4 pixels without bounds checking.
+                dst_pixels[dstRowOffset + x] = src_pixels[final_y0 * pitchPixels + final_x0];
+                dst_pixels[dstRowOffset + x + 1] = src_pixels[final_y1 * pitchPixels + final_x1];
+                dst_pixels[dstRowOffset + x + 2] = src_pixels[final_y2 * pitchPixels + final_x2];
+                dst_pixels[dstRowOffset + x + 3] = src_pixels[final_y3 * pitchPixels + final_x3];
+            }
+
+            // Handle remaining pixels.
+            for (; x < width; ++x) {
+                int final_x = Fix2Int(src_x);
+                int final_y = Fix2Int(src_y);
+                dst_pixels[dstRowOffset + x] = src_pixels[final_y * pitchPixels + final_x];
+                src_x += dx_cos;
+                src_y += dx_sin;
+            }
+        } else {
+            // Slow path: Bounds checking required.
             for (; x < width - 3; x += 4) {
                 // Pixel 0
                 int final_x0 = Fix2Int(src_x);
@@ -223,6 +303,7 @@ void ApplyRotation(void *dest, void *source, int pitch, int width, int height, T
                 src_y += dx_sin;
             }
         }
+    }
 }
 
 void ApplyScale(void *dest, void *source, int pitch, int width, int height, TFixed center_x, TFixed center_y, TFixed scale_x, TFixed scale_y)
@@ -230,6 +311,13 @@ void ApplyScale(void *dest, void *source, int pitch, int width, int height, TFix
     TUint16 *src_pixels = static_cast<TUint16 *>(source);
     TUint16 *dst_pixels = static_cast<TUint16 *>(dest);
 
+    // Fast path: Identity scale; just copy entire buffer.
+    const TFixed identity = Int2Fix(1);
+    if (scale_x == identity && scale_y == identity) {
+        Mem::Copy(dest, source, pitch * height);
+        return;
+    }
+
     // Pre-calculate pitch in pixels to avoid repeated division.
     const TInt pitchPixels = pitch >> 1;