Fixes the type of view size.

This commit changes the type of the view size accepted by `nvgRenderFrame()` from `int` to `float` so it matches the type defined in `GLNVGcontext`. This would prevent a framebuffer missing a pixel in final rendering result.

src/nanovg.c

@@ -363,7 +363,7 @@ void nvgDeleteInternal(NVGcontext* ctx)
 	free(ctx);
 }
 
-void nvgBeginFrame(NVGcontext* ctx, int windowWidth, int windowHeight, float devicePixelRatio)
+void nvgBeginFrame(NVGcontext* ctx, float windowWidth, float windowHeight, float devicePixelRatio)
 {
 /*	printf("Tris: draws:%d  fill:%d  stroke:%d  text:%d  TOT:%d\n",
 		ctx->drawCallCount, ctx->fillTriCount, ctx->strokeTriCount, ctx->textTriCount,

src/nanovg.h

@@ -152,7 +152,7 @@ enum NVGimageFlags {
 // For example, GLFW returns two dimension for an opened window: window size and
 // frame buffer size. In that case you would set windowWidth/Height to the window size
 // devicePixelRatio to: frameBufferWidth / windowWidth.
-void nvgBeginFrame(NVGcontext* ctx, int windowWidth, int windowHeight, float devicePixelRatio);
+void nvgBeginFrame(NVGcontext* ctx, float windowWidth, float windowHeight, float devicePixelRatio);
 
 // Cancels drawing the current frame.
 void nvgCancelFrame(NVGcontext* ctx);
@@ -653,7 +653,7 @@ struct NVGparams {
 	int (*renderDeleteTexture)(void* uptr, int image);
 	int (*renderUpdateTexture)(void* uptr, int image, int x, int y, int w, int h, const unsigned char* data);
 	int (*renderGetTextureSize)(void* uptr, int image, int* w, int* h);
-	void (*renderViewport)(void* uptr, int width, int height, float devicePixelRatio);
+	void (*renderViewport)(void* uptr, float width, float height, float devicePixelRatio);
 	void (*renderCancel)(void* uptr);
 	void (*renderFlush)(void* uptr);
 	void (*renderFill)(void* uptr, NVGpaint* paint, NVGcompositeOperationState compositeOperation, NVGscissor* scissor, float fringe, const float* bounds, const NVGpath* paths, int npaths);

src/nanovg_gl.h

@@ -989,12 +989,12 @@ static void glnvg__setUniforms(GLNVGcontext* gl, int uniformOffset, int image)
 	}
 }
 
-static void glnvg__renderViewport(void* uptr, int width, int height, float devicePixelRatio)
+static void glnvg__renderViewport(void* uptr, float width, float height, float devicePixelRatio)
 {
 	NVG_NOTUSED(devicePixelRatio);
 	GLNVGcontext* gl = (GLNVGcontext*)uptr;
-	gl->view[0] = (float)width;
-	gl->view[1] = (float)height;
+	gl->view[0] = width;
+	gl->view[1] = height;
 }
 
 static void glnvg__fill(GLNVGcontext* gl, GLNVGcall* call)