draw rect

src/CMakeLists.txt

@@ -1,3 +1,6 @@
+add_executable(draw_rect draw_rect.cc ${commom_src})
+target_link_libraries (draw_rect ${FC_DEP_LIBS})
+
 add_executable(draw_filled_rect draw_filled_rect.cc ${commom_src})
 target_link_libraries (draw_filled_rect ${FC_DEP_LIBS})
 

src/Raster.cc

@@ -195,25 +195,35 @@ void Raster::drawArray(DRAWMODE mode, const float2* points, size_t count) {
 void Raster::drawFilledRect(int startX, int startY, int width, int height) {
 
     /*越界部分不描画*/
-    if (startX < 0) {
-        startX = 0;
-    }
+    int left = tmax<int>(startX, 0);
+    int bottom = tmax<int>(startY, 0);
 
-    if (startY < 0) {
-        startY = 0;
-    }
+    int right = tmin<int>(startX + width, _width);
+    int top = tmin<int>(startY + height, _height);
 
-    if (startX + width > _width) {
-        width = _width - startX;
+    for (int x = left; x < right; x++) {
+        for (int y = bottom; y < top; y++) {
+            drawPoint(x, y, Rgba(255, 0, 0, 0));
+        }
     }
+}
 
-    if (startY + height > _height) {
-        height = _height - startY;
-    }
+void Raster::drawRect(const int2* points, const Rgba* colors) {
+    int left = tmax<int>(points[0].x, 0);
+    int bottom = tmax<int>(points[0].y, 0);
 
-    for (int x = startX; x < startX + width; x++) {
-        for (int y = startY; y < startY + height; y++) {
-            drawPoint(x, y, Rgba(255, 0, 0, 0));
+    int right = tmin<int>(points[2].x, _width);
+    int top = tmin<int>(points[2].y, _height);
+
+    float w = right - left;
+    float h = top - bottom;
+
+    for (int x = left; x < right; ++x) {
+        Rgba color1 = colorLerp(colors[0], colors[1], (x - left) / w);
+        Rgba color2 = colorLerp(colors[3], colors[2], (x - left) / w);
+        for (int y = bottom; y < top; ++y) {
+            Rgba color = colorLerp(color1, color2, (y - bottom) / h);
+            drawPoint(x, y, color);
         }
     }
 }

src/Raster.h

@@ -33,6 +33,7 @@ public:
     void drawLine(float2 p1, float2 p2, Rgba color1, Rgba color2);
     void drawArray(DRAWMODE mode, const float2* points, size_t count);
     void drawFilledRect(int startX, int startY, int width, int height);
+    void drawRect(const int2* points, const Rgba* colors);
     int size();
     void clean();
     bool setPixel(int x, int y, Rgba color);

src/common.h

@@ -20,6 +20,14 @@
 #define die(m) do { perror(m); exit(EXIT_FAILURE); } while(0)
 #define def2rad(theta) (0.01745329251994329 * (theta)) //每个角度所对应的弧度
 
+template<class T> inline T tmin(T a, T b) {
+    return a < b ? a : b;
+}
+
+template<class T> inline T tmax(T a, T b) {
+    return a > b ? a : b;
+}
+
 template<typename T>
 struct tvec2 {
     typedef T value_type;
@@ -56,6 +64,7 @@ struct tvec2 {
 
 
 typedef tvec2<float> float2;
+typedef tvec2<int> int2;
 
 #endif /* COMMON_H */
 

src/draw_rect.cc

@@ -0,0 +1,86 @@
+#include <iostream>
+#include <math.h>
+#include <cairo.h>
+#include <gtk/gtk.h>
+#include "Rgba.h"
+#include "Raster.h"
+#include "common.h"
+
+using namespace std;
+
+
+gint height = 500;
+gint width = 500;
+
+Raster raster(width, height);
+
+unsigned char* makeBitmap() {
+    raster.clean();
+
+    for (int i = 0; i < 10000; i++) {
+        raster.drawPoint(rand() % height, rand() % width, Rgba(255, 0, 0), 3);
+    }
+
+    int2 points[] = {
+        int2(50, 50),
+        int2(250, 50),
+        int2(250, 250),
+        int2(50, 250)
+    };
+
+    Rgba colors[] = {
+        Rgba(255, 0, 0, 0),
+        Rgba(0, 255, 0, 0),
+        Rgba(0, 0, 255, 0),
+        Rgba(255, 255, 255, 0),
+    };
+
+    raster.drawRect(points, colors);
+
+    return (unsigned char*) raster.buffer;
+}
+
+void render(GtkWidget *widget) {
+    //允许窗口可以绘图
+    gtk_widget_set_app_paintable(widget, TRUE);
+    gtk_widget_realize(widget);
+    gtk_widget_queue_draw(widget);
+
+    //模拟一张图片
+    unsigned char* data = makeBitmap();
+
+    GdkPixbuf *pixbuf = gdk_pixbuf_new_from_data(data, GDK_COLORSPACE_RGB, TRUE, 8, width, height, width * 4, NULL, NULL);
+
+    GdkPixmap *pixmap = NULL;
+
+    gdk_pixbuf_render_pixmap_and_mask(pixbuf, &pixmap, NULL, 128);
+
+    gdk_window_set_back_pixmap(widget->window, pixmap, FALSE);
+
+    g_object_unref(pixbuf);
+    g_object_unref(pixmap);
+    //delete data;
+}
+
+int main(int argc, char* argv[]) {
+
+    gtk_init(&argc, &argv);
+
+    //创建窗口
+    GtkWidget *window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
+    gtk_widget_set_size_request(window, width, height);
+
+    gtk_window_set_title(GTK_WINDOW(window), "Gtk testing");
+    gtk_window_set_position(GTK_WINDOW(window), GTK_WIN_POS_CENTER_ALWAYS);
+
+    //窗口关闭时候，关闭程序
+    g_signal_connect(window, "destroy", G_CALLBACK(gtk_main_quit), NULL);
+    //设置渲染
+    g_signal_connect(window, "expose-event", G_CALLBACK(render), window);
+
+
+    gtk_widget_show_all(window);
+    gtk_main();
+
+    return 0;
+}