113 lines
2.4 KiB
C++
113 lines
2.4 KiB
C++
#include "Gpu.h"
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GPU::GPU() {}
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GPU::~GPU() {
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if (mFrameBuffer) {
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delete mFrameBuffer;
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}
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}
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void GPU::initGL(const uint32_t& width, const uint32_t& height, void* buffer) {
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m_screenWidth = width;
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m_screenHeight = height;
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mFrameBuffer = new FrameBuffer(width, height, buffer);
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}
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void GPU::clear() {
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std::fill_n(mFrameBuffer->mColorBuffer, mFrameBuffer->mPixelSize, RGBA(0, 0, 0, 0));
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std::fill_n(mFrameBuffer->mDepthBuffer, mFrameBuffer->mPixelSize, FLT_MAX);
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}
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void GPU::drawPoint(const int& x, const int& y, const RGBA& color, const float& depth) {
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//从窗口左下角开始算起
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if (x < 0 || x >= m_screenWidth || y < 0 || y >= m_screenHeight) { return; }
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uint32_t pixelPos = y * mFrameBuffer->mWidth + x;
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/*depth-test*/
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if (depth > mFrameBuffer->mDepthBuffer[pixelPos]) { return; }
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mFrameBuffer->mColorBuffer[pixelPos] = color;
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mFrameBuffer->mDepthBuffer[pixelPos] = depth;
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}
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void GPU::drawVerticalLine(const int& x, const int& y_min, const int y_max, const RGBA& color, const float& depth)
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{
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for (int i = std::max(y_min,0); i <= std::min(y_max,SCREEN_HEIGHT); i++)
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{
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drawPoint(x, i, color, depth);
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}
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}
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void GPU::drawRect(const int& x_min, const int x_max, const int y_min, const int y_max, const RGBA& color, const float& depth)
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{
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for (int i = x_min; i <= x_max; i++)
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{
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drawVerticalLine(i, y_min, y_max, color, depth);
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}
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}
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void GPU::drawLine(const int& x_from, const int& y_from, const int& x_to, const int& y_to, const RGBA& color, const float& depth)
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{
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int disX = abs((int)(x_to - x_from));
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int disY = abs((int)(y_to - y_from));
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int xNow = x_from;
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int yNow = y_from;
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int stepX = 0;
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int stepY = 0;
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stepX = (x_to > x_from) ? 1 : ((x_to < x_from) ? -1 : 0);
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stepY = (y_to > y_from) ? 1 : ((y_to < y_from) ? -1 : 0);
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bool useXStep = true;
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if (disX < disY)
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{
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useXStep = false;
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SWAP_INT(disX, disY);
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}
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int sumStep = disX;
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int p = 2 * disY - disX;
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for (int i = 0; i < sumStep; i++)
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{
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float _scale = 0;
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if (useXStep)
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{
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if (x_to != x_from)
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{
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_scale = (float)(xNow - x_from) / (float)(x_to - x_from);
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}
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}
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else
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{
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if (y_to != y_from)
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{
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_scale = (float)(yNow - y_from) / (float)(y_to - y_from);
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}
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}
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drawPoint(xNow, yNow, color);
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if (p >= 0)
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{
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if (useXStep)
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{
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yNow += stepY;
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}
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else
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{
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xNow += stepX;
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}
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p -= 2 * disX;
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}
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if (useXStep)
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{
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xNow += stepX;
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}
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else
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{
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yNow += stepY;
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}
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p += 2 * disY;
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}
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}
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