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[N-Gage] Add various micro-optimizations to rendering back-end

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- Add reusable line points buffer to eliminate per-call heap allocations in DrawLines.
- Cache last draw color to skip redundant SetPenColor/SetBrushColor calls.
- Pre-compute cardinal angle constants (0°, 90°, 180°, 270°) for CopyEx fast-path.
- Cache color modulation state to avoid redundant LUT rebuilds.
- Add missing break statement in HandleEvent.
- Initialize previously uninitialized lastTime variable in UpdateFPS.
This commit is contained in:
Michael Fitzmayer 2026-04-16 20:50:34 +02:00
parent 847fc72b1b
commit b53b31b74a
3 changed files with 125 additions and 74 deletions
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40
src/render/ngage/SDL_render_ops.cpp
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@ -36,12 +36,12 @@ void ApplyColorMod(void *dest, void *source, int pitch, int width, int height, S
const TUint8 *lut_g = colorLUT + 256;
const TUint8 *lut_b = colorLUT + 512;
// Process 4 pixels at a time (loop unrolling).
// Process 4 pixels at a time.
for (int y = 0; y < height; ++y) {
const TInt rowOffset = y * pitchPixels;
int x = 0;
// Unrolled loop: process 4 pixels at once with optimized bit manipulation.
// Process 4 pixels at once with optimized bit manipulation.
for (; x < width - 3; x += 4) {
// Load 4 pixels at once.
TUint16 p0 = src_pixels[rowOffset + x];
@ -51,9 +51,9 @@ void ApplyColorMod(void *dest, void *source, int pitch, int width, int height, S
// Pixel 0: Extract and modulate RGB4444 components.
// RGB4444 format: RRRR GGGG BBBB xxxx
TUint8 r0 = lut_r[(p0 >> 8) & 0xF0]; // Extract R (bits 12-15), shift to byte position
TUint8 g0 = lut_g[(p0 >> 3) & 0xF8]; // Extract G (bits 6-9), scale to 8-bit
TUint8 b0 = lut_b[(p0 << 3) & 0xF8]; // Extract B (bits 0-3), scale to 8-bit
TUint8 r0 = lut_r[(p0 >> 8) & 0xF0]; // Extract R (bits 12-15), shift to byte position
TUint8 g0 = lut_g[(p0 >> 3) & 0xF8]; // Extract G (bits 6-9), scale to 8-bit
TUint8 b0 = lut_b[(p0 << 3) & 0xF8]; // Extract B (bits 0-3), scale to 8-bit
dst_pixels[rowOffset + x] = ((r0 & 0xF0) << 8) | ((g0 & 0xF0) << 3) | ((b0 & 0xF0) >> 1);
// Pixel 1
@ -112,7 +112,7 @@ void ApplyFlip(void *dest, void *source, int pitch, int width, int height, SDL_F
int x = 0;
// Unrolled loop: process 4 pixels at once.
// Process 4 pixels at once.
for (; x < width - 3; x += 4) {
if (flipHorizontal) {
dst_pixels[dstRowOffset + x] = src_pixels[srcRowOffset + (width_m1 - x)];
@ -172,7 +172,7 @@ void ApplyRotation(void *dest, void *source, int pitch, int width, int height, T
int x = 0;
// Unrolled loop: process 4 pixels at once.
// Process 4 pixels at once.
for (; x < width - 3; x += 4) {
// Pixel 0
int final_x0 = Fix2Int(src_x);
@ -199,14 +199,10 @@ void ApplyRotation(void *dest, void *source, int pitch, int width, int height, T
src_y += dx_sin;
// Write all 4 pixels with bounds checking.
dst_pixels[dstRowOffset + x] = (final_x0 >= 0 && final_x0 < width && final_y0 >= 0 && final_y0 < height) ?
src_pixels[final_y0 * pitchPixels + final_x0] : 0;
dst_pixels[dstRowOffset + x + 1] = (final_x1 >= 0 && final_x1 < width && final_y1 >= 0 && final_y1 < height) ?
src_pixels[final_y1 * pitchPixels + final_x1] : 0;
dst_pixels[dstRowOffset + x + 2] = (final_x2 >= 0 && final_x2 < width && final_y2 >= 0 && final_y2 < height) ?
src_pixels[final_y2 * pitchPixels + final_x2] : 0;
dst_pixels[dstRowOffset + x + 3] = (final_x3 >= 0 && final_x3 < width && final_y3 >= 0 && final_y3 < height) ?
src_pixels[final_y3 * pitchPixels + final_x3] : 0;
dst_pixels[dstRowOffset + x] = (final_x0 >= 0 && final_x0 < width && final_y0 >= 0 && final_y0 < height) ? src_pixels[final_y0 * pitchPixels + final_x0] : 0;
dst_pixels[dstRowOffset + x + 1] = (final_x1 >= 0 && final_x1 < width && final_y1 >= 0 && final_y1 < height) ? src_pixels[final_y1 * pitchPixels + final_x1] : 0;
dst_pixels[dstRowOffset + x + 2] = (final_x2 >= 0 && final_x2 < width && final_y2 >= 0 && final_y2 < height) ? src_pixels[final_y2 * pitchPixels + final_x2] : 0;
dst_pixels[dstRowOffset + x + 3] = (final_x3 >= 0 && final_x3 < width && final_y3 >= 0 && final_y3 < height) ? src_pixels[final_y3 * pitchPixels + final_x3] : 0;
}
// Handle remaining pixels.
@ -265,7 +261,7 @@ void ApplyScale(void *dest, void *source, int pitch, int width, int height, TFix
int x = 0;
// Unrolled loop: process 4 pixels at once.
// Process 4 pixels at once.
for (; x < width - 3; x += 4) {
// Process 4 pixels using incremental approach.
int final_x0 = Fix2Int(src_x);
@ -278,14 +274,10 @@ void ApplyScale(void *dest, void *source, int pitch, int width, int height, TFix
src_x += inv_scale_x;
// Write all 4 pixels with bounds checking.
dst_pixels[dstRowOffset + x] = (rowInBounds && final_x0 >= 0 && final_x0 < width) ?
src_pixels[srcRowOffset + final_x0] : 0;
dst_pixels[dstRowOffset + x + 1] = (rowInBounds && final_x1 >= 0 && final_x1 < width) ?
src_pixels[srcRowOffset + final_x1] : 0;
dst_pixels[dstRowOffset + x + 2] = (rowInBounds && final_x2 >= 0 && final_x2 < width) ?
src_pixels[srcRowOffset + final_x2] : 0;
dst_pixels[dstRowOffset + x + 3] = (rowInBounds && final_x3 >= 0 && final_x3 < width) ?
src_pixels[srcRowOffset + final_x3] : 0;
dst_pixels[dstRowOffset + x] = (rowInBounds && final_x0 >= 0 && final_x0 < width) ? src_pixels[srcRowOffset + final_x0] : 0;
dst_pixels[dstRowOffset + x + 1] = (rowInBounds && final_x1 >= 0 && final_x1 < width) ? src_pixels[srcRowOffset + final_x1] : 0;
dst_pixels[dstRowOffset + x + 2] = (rowInBounds && final_x2 >= 0 && final_x2 < width) ? src_pixels[srcRowOffset + final_x2] : 0;
dst_pixels[dstRowOffset + x + 3] = (rowInBounds && final_x3 >= 0 && final_x3 < width) ? src_pixels[srcRowOffset + final_x3] : 0;
}
// Handle remaining pixels.